Strict types

32 files changed, 137 insertions, 124 deletions

diff --git a/app/GedcomRecord.php b/app/GedcomRecord.php
index 8c21b44989..da8b3ba417 100644
--- a/app/GedcomRecord.php
+++ b/app/GedcomRecord.php
@@ -956,7 +956,7 @@ class GedcomRecord
             } elseif (preg_match_all('/\n(\d) ' . Gedcom::REGEX_TAG . ' ' . $value . '/', $fact->gedcom(), $matches, PREG_SET_ORDER)) {
                 $gedcom = $fact->gedcom();
                 foreach ($matches as $match) {
-                    $next_level  = $match[1] + 1;
+                    $next_level  = 1 + (int) $match[1];
                     $next_levels = '[' . $next_level . '-9]';
                     $gedcom      = preg_replace('/' . $match[0] . '(\n' . $next_levels . '.*)*/', '', $gedcom);
                 }
diff --git a/app/Individual.php b/app/Individual.php
index 460102fbbc..8478f95b32 100644
--- a/app/Individual.php
+++ b/app/Individual.php
@@ -974,8 +974,8 @@ class Individual extends GedcomRecord
         ////////////////////////////////////////////////////////////////////////////
 
         $sublevel = 1 + (int) substr($gedcom, 0, 1);
-        $GIVN     = preg_match('/\n' . $sublevel . ' GIVN (.+)/', $gedcom, $match) ? $match[1] : '';
-        $SURN     = preg_match('/\n' . $sublevel . ' SURN (.+)/', $gedcom, $match) ? $match[1] : '';
+        $GIVN     = preg_match('/\n' . $sublevel . ' GIVN (.+)/', $gedcom, $match) === 1 ? $match[1] : '';
+        $SURN     = preg_match('/\n' . $sublevel . ' SURN (.+)/', $gedcom, $match) === 1 ? $match[1] : '';
 
         // SURN is an comma-separated list of surnames...
         if ($SURN !== '') {
diff --git a/app/Services/GedcomImportService.php b/app/Services/GedcomImportService.php
index b45b4f2c18..e0f07fb2a0 100644
--- a/app/Services/GedcomImportService.php
+++ b/app/Services/GedcomImportService.php
@@ -157,12 +157,18 @@ class GedcomImportService
                     // Consistent commas
                     $data = preg_replace('/ *[,，،] */u', ', ', $data);
                     // The Master Genealogist stores LAT/LONG data in the PLAC field, e.g. Pennsylvania, USA, 395945N0751013W
-                    if (preg_match('/(.*), (\d\d)(\d\d)(\d\d)([NS])(\d\d\d)(\d\d)(\d\d)([EW])$/', $data, $match)) {
+                    if (preg_match('/(.*), (\d\d)(\d\d)(\d\d)([NS])(\d\d\d)(\d\d)(\d\d)([EW])$/', $data, $match) === 1) {
+                        $degns = (int) $match[2];
+                        $minns = (int) $match[3];
+                        $secns = (int) $match[4];
+                        $degew = (int) $match[6];
+                        $minew = (int) $match[7];
+                        $secew = (int) $match[8];
                         $data =
                             $match[1] . "\n" .
-                            ($level + 1) . " MAP\n" .
-                            ($level + 2) . ' LATI ' . ($match[5] . round($match[2] + ($match[3] / 60) + ($match[4] / 3600), 4)) . "\n" .
-                            ($level + 2) . ' LONG ' . ($match[9] . round($match[6] + ($match[7] / 60) + ($match[8] / 3600), 4));
+                            (1 + (int) $level) . " MAP\n" .
+                            (2 + (int) $level) . ' LATI ' . ($match[5] . round($degns + $minns / 60 + $secns / 3600, 4)) . "\n" .
+                            (2 + (int) $level) . ' LONG ' . ($match[9] . round($degew + $minew / 60 + $secew / 3600, 4));
                     }
                     break;
                 case 'SEX':
diff --git a/app/Services/RelationshipService.php b/app/Services/RelationshipService.php
index c63bb9fb2f..97e9a789e5 100644
--- a/app/Services/RelationshipService.php
+++ b/app/Services/RelationshipService.php
@@ -333,9 +333,9 @@ class RelationshipService
 
         // The sex of the last person in the relationship determines the name in
         // many cases. e.g. great-aunt / great-uncle
-        if (preg_match('/(fat|hus|son|bro)$/', $path)) {
+        if (preg_match('/(fat|hus|son|bro)$/', $path) === 1) {
             $sex2 = 'M';
-        } elseif (preg_match('/(mot|wif|dau|sis)$/', $path)) {
+        } elseif (preg_match('/(mot|wif|dau|sis)$/', $path) === 1) {
             $sex2 = 'F';
         } else {
             $sex2 = 'U';
@@ -1198,116 +1198,116 @@ class RelationshipService
         }
 
         // Some “special case” level five relationships that have specific names in certain languages
-        if (preg_match('/^(mot|fat|par)fatbro(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatbro(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandfather’s brother’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatbro(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatbro(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandfather’s brother’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatbro(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatbro(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandfather’s brother’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatsis(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatsis(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandfather’s sister’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatsis(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatsis(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandfather’s sister’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatsis(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatsis(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandfather’s sister’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatsib(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatsib(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandfather’s sibling’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatsib(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatsib(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandfather’s sibling’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)fatsib(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)fatsib(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandfather’s sibling’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motbro(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motbro(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandmother’s brother’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motbro(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motbro(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandmother’s brother’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motbro(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motbro(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandmother’s brother’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motsis(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motsis(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandmother’s sister’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motsis(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motsis(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandmother’s sister’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motsis(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motsis(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandmother’s sister’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motsib(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motsib(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandmother’s sibling’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motsib(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motsib(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandmother’s sibling’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)motsib(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)motsib(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandmother’s sibling’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parbro(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parbro(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandparent’s brother’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parbro(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parbro(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandparent’s brother’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parbro(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parbro(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandparent’s brother’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parsis(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parsis(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandparent’s sister’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parsis(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parsis(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandparent’s sister’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parsis(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parsis(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandparent’s sister’s grandchild', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parsib(son|dau|chi)dau$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parsib(son|dau|chi)dau$/', $path) === 1) {
             return I18N::translateContext('grandparent’s sibling’s granddaughter', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parsib(son|dau|chi)son$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parsib(son|dau|chi)son$/', $path) === 1) {
             return I18N::translateContext('grandparent’s sibling’s grandson', 'second cousin');
         }
 
-        if (preg_match('/^(mot|fat|par)parsib(son|dau|chi)chi$/', $path)) {
+        if (preg_match('/^(mot|fat|par)parsib(son|dau|chi)chi$/', $path) === 1) {
             return I18N::translateContext('grandparent’s sibling’s grandchild', 'second cousin');
         }
 
         // Look for generic/pattern relationships.
-        if (preg_match('/^((?:mot|fat|par)+)(bro|sis|sib)$/', $path, $match)) {
+        if (preg_match('/^((?:mot|fat|par)+)(bro|sis|sib)$/', $path, $match) === 1) {
             // siblings of direct ancestors
             $up       = intdiv(strlen($match[1]), 3);
             $bef_last = substr($path, -6, 3);
@@ -1515,7 +1515,7 @@ class RelationshipService
                     }
             }
         }
-        if (preg_match('/^(?:bro|sis|sib)((?:son|dau|chi)+)$/', $path, $match)) {
+        if (preg_match('/^(?:bro|sis|sib)((?:son|dau|chi)+)$/', $path, $match) === 1) {
             // direct descendants of siblings
             $down  = intdiv(strlen($match[1]), 3) + 1; // Add one, as we count generations from the common ancestor
             $first = substr($path, 0, 3);
@@ -1808,7 +1808,7 @@ class RelationshipService
                     }
             }
         }
-        if (preg_match('/^((?:mot|fat|par)*)$/', $path, $match)) {
+        if (preg_match('/^((?:mot|fat|par)*)$/', $path, $match) === 1) {
             // direct ancestors
             $up = intdiv(strlen($match[1]), 3);
             switch ($up) {
@@ -1965,7 +1965,7 @@ class RelationshipService
                     }
             }
         }
-        if (preg_match('/^((?:son|dau|chi)*)$/', $path, $match)) {
+        if (preg_match('/^((?:son|dau|chi)*)$/', $path, $match) === 1) {
             // direct descendants
             $up = intdiv(strlen($match[1]), 3);
             switch ($up) {
@@ -2099,7 +2099,7 @@ class RelationshipService
                     }
             }
         }
-        if (preg_match('/^((?:mot|fat|par)+)(?:bro|sis|sib)((?:son|dau|chi)+)$/', $path, $match)) {
+        if (preg_match('/^((?:mot|fat|par)+)(?:bro|sis|sib)((?:son|dau|chi)+)$/', $path, $match) === 1) {
             // cousins in English
             $ascent  = $match[1];
             $descent = $match[2];
diff --git a/app/Services/SearchService.php b/app/Services/SearchService.php
index de30265d79..d4fb041613 100644
--- a/app/Services/SearchService.php
+++ b/app/Services/SearchService.php
@@ -516,7 +516,7 @@ class SearchService
      */
     public function searchIndividualsAdvanced(array $trees, array $fields, array $modifiers): Collection
     {
-        $fields = array_filter($fields);
+        $fields = array_filter($fields, static fn (string $x): bool => $x !== '');
 
         $query = DB::table('individuals')
             ->select(['individuals.*'])
@@ -535,28 +535,26 @@ class SearchService
         $fam_plac      = false;
 
         foreach ($fields as $field_name => $field_value) {
-            if ($field_value !== '') {
-                if (str_starts_with($field_name, 'FATHER:NAME')) {
-                    $father_name = true;
-                } elseif (str_starts_with($field_name, 'MOTHER:NAME')) {
-                    $mother_name = true;
-                } elseif (str_starts_with($field_name, 'INDI:NAME:GIVN')) {
-                    $indi_name = true;
-                } elseif (str_starts_with($field_name, 'INDI:NAME:SURN')) {
-                    $indi_name = true;
-                } elseif (str_starts_with($field_name, 'FAM:')) {
-                    $spouse_family = true;
-                    if (str_ends_with($field_name, ':DATE')) {
-                        $fam_dates[] = explode(':', $field_name)[1];
-                    } elseif (str_ends_with($field_name, ':PLAC')) {
-                        $fam_plac = true;
-                    }
-                } elseif (str_starts_with($field_name, 'INDI:')) {
-                    if (str_ends_with($field_name, ':DATE')) {
-                        $indi_dates[] = explode(':', $field_name)[1];
-                    } elseif (str_ends_with($field_name, ':PLAC')) {
-                        $indi_plac = true;
-                    }
+            if (str_starts_with($field_name, 'FATHER:NAME')) {
+                $father_name = true;
+            } elseif (str_starts_with($field_name, 'MOTHER:NAME')) {
+                $mother_name = true;
+            } elseif (str_starts_with($field_name, 'INDI:NAME:GIVN')) {
+                $indi_name = true;
+            } elseif (str_starts_with($field_name, 'INDI:NAME:SURN')) {
+                $indi_name = true;
+            } elseif (str_starts_with($field_name, 'FAM:')) {
+                $spouse_family = true;
+                if (str_ends_with($field_name, ':DATE')) {
+                    $fam_dates[] = explode(':', $field_name)[1];
+                } elseif (str_ends_with($field_name, ':PLAC')) {
+                    $fam_plac = true;
+                }
+            } elseif (str_starts_with($field_name, 'INDI:')) {
+                if (str_ends_with($field_name, ':DATE')) {
+                    $indi_dates[] = explode(':', $field_name)[1];
+                } elseif (str_ends_with($field_name, ':PLAC')) {
+                    $indi_plac = true;
                 }
             }
         }
@@ -882,7 +880,7 @@ class SearchService
                     if (str_starts_with($field_name, 'INDI:NAME:') && $field_name !== 'INDI:NAME:GIVN' && $field_name !== 'INDI:NAME:SURN') {
                         $regex = '/\n1 NAME.*(?:\n2.*)*\n2 ' . $parts[2] . ' .*' . preg_quote($field_value, '/') . '/i';
 
-                        if (preg_match($regex, $individual->gedcom())) {
+                        if (preg_match($regex, $individual->gedcom()) === 1) {
                             continue;
                         }
 
@@ -893,7 +891,7 @@ class SearchService
 
                     if (str_starts_with($field_name, 'INDI:') && str_ends_with($field_name, ':PLAC')) {
                         foreach ($individual->facts([$parts[1]]) as $fact) {
-                            if (preg_match($regex, $fact->place()->gedcomName())) {
+                            if (preg_match($regex, $fact->place()->gedcomName()) === 1) {
                                 continue 2;
                             }
                         }
@@ -903,7 +901,7 @@ class SearchService
                     if (str_starts_with($field_name, 'FAM:') && str_ends_with($field_name, ':PLAC')) {
                         foreach ($individual->spouseFamilies() as $family) {
                             foreach ($family->facts([$parts[1]]) as $fact) {
-                                if (preg_match($regex, $fact->place()->gedcomName())) {
+                                if (preg_match($regex, $fact->place()->gedcomName()) === 1) {
                                     continue 3;
                                 }
                             }
@@ -913,7 +911,7 @@ class SearchService
 
                     if ($field_name === 'INDI:FACT:TYPE' || $field_name === 'INDI:EVEN:TYPE' || $field_name === 'INDI:CHAN:_WT_USER') {
                         foreach ($individual->facts([$parts[1]]) as $fact) {
-                            if (preg_match($regex, $fact->attribute($parts[2]))) {
+                            if (preg_match($regex, $fact->attribute($parts[2])) === 1) {
                                 continue 2;
                             }
                         }
@@ -923,7 +921,7 @@ class SearchService
 
                     if (str_starts_with($field_name, 'INDI:')) {
                         foreach ($individual->facts([$parts[1]]) as $fact) {
-                            if (preg_match($regex, $fact->value())) {
+                            if (preg_match($regex, $fact->value()) === 1) {
                                 continue 2;
                             }
                         }
@@ -934,7 +932,7 @@ class SearchService
                     if (str_starts_with($field_name, 'FAM:')) {
                         foreach ($individual->spouseFamilies() as $family) {
                             foreach ($family->facts([$parts[1]]) as $fact) {
-                                if (preg_match($regex, $fact->value())) {
+                                if (preg_match($regex, $fact->value()) === 1) {
                                     continue 3;
                                 }
                             }
diff --git a/app/Soundex.php b/app/Soundex.php
index 7c92f5d2bb..5835c14f95 100644
--- a/app/Soundex.php
+++ b/app/Soundex.php
@@ -712,7 +712,7 @@ class Soundex
 
         // Loop through the input string.
         // Stop when the string is exhausted or when no more partial results remain
-        while (count($partialResult) !== 0 && $currPos <= $lastPos) {
+        while ($partialResult !== [] && $currPos <= $lastPos) {
             // Find the DM coding table entry for the chunk at the current position
             $thisEntry = substr($name, $currPos, self::MAXCHAR); // Get maximum length chunk
             while ($thisEntry !== '') {
@@ -781,7 +781,7 @@ class Soundex
                             // We're looking for 7 entries because the first is '!' and doesn't count
                             $tempResult = str_replace('!', '', implode('', $workingEntry));
                             // Only return codes from recognisable sounds
-                            if ($tempResult) {
+                            if ($tempResult !== '') {
                                 $result[] = substr($tempResult . '000000', 0, 6);
                             }
                         }
@@ -795,7 +795,7 @@ class Soundex
         foreach ($partialResult as $workingEntry) {
             $tempResult = str_replace('!', '', implode('', $workingEntry));
             // Only return codes from recognisable sounds
-            if ($tempResult) {
+            if ($tempResult !== '') {
                 $result[] = substr($tempResult . '000000', 0, 6);
             }
         }
diff --git a/app/Source.php b/app/Source.php
index 81ea5f9843..a8293d5274 100644
--- a/app/Source.php
+++ b/app/Source.php
@@ -44,7 +44,7 @@ class Source extends GedcomRecord
         preg_match_all('/\n1 REPO @(.+)@/', $this->gedcom, $matches);
         foreach ($matches[1] as $match) {
             $repo = Registry::repositoryFactory()->make($match, $this->tree);
-            if ($repo && !$repo->canShow($access_level)) {
+            if ($repo instanceof Repository && !$repo->canShow($access_level)) {
                 return false;
             }
         }
diff --git a/app/Statistics/Google/ChartFamilyLargest.php b/app/Statistics/Google/ChartFamilyLargest.php
index b8e48206fc..b89c8ab563 100644
--- a/app/Statistics/Google/ChartFamilyLargest.php
+++ b/app/Statistics/Google/ChartFamilyLargest.php
@@ -19,6 +19,7 @@ declare(strict_types=1);
 
 namespace Fisharebest\Webtrees\Statistics\Google;
 
+use Fisharebest\Webtrees\Family;
 use Fisharebest\Webtrees\I18N;
 use Fisharebest\Webtrees\Registry;
 use Fisharebest\Webtrees\Statistics\Service\ColorService;
@@ -94,7 +95,7 @@ class ChartFamilyLargest
         foreach ($this->queryRecords($total) as $record) {
             $family = Registry::familyFactory()->make($record->id, $this->tree);
 
-            if ($family && $family->canShow()) {
+            if ($family instanceof Family && $family->canShow()) {
                 $data[] = [
                     htmlspecialchars_decode(strip_tags($family->fullName())),
                     $record->total
diff --git a/app/Statistics/Google/ChartFamilyWithSources.php b/app/Statistics/Google/ChartFamilyWithSources.php
index 514dda4457..6114264b0f 100644
--- a/app/Statistics/Google/ChartFamilyWithSources.php
+++ b/app/Statistics/Google/ChartFamilyWithSources.php
@@ -66,7 +66,7 @@ class ChartFamilyWithSources
             ],
         ];
 
-        if ($tot_fam || $tot_fam_source) {
+        if ($tot_fam > 0 || $tot_fam_source > 0) {
             $data[] = [
                 I18N::translate('Without sources'),
                 $tot_fam - $tot_fam_source
diff --git a/app/Statistics/Google/ChartIndividualWithSources.php b/app/Statistics/Google/ChartIndividualWithSources.php
index 1e2815b99a..114bba0b62 100644
--- a/app/Statistics/Google/ChartIndividualWithSources.php
+++ b/app/Statistics/Google/ChartIndividualWithSources.php
@@ -66,7 +66,7 @@ class ChartIndividualWithSources
             ],
         ];
 
-        if ($tot_indi || $tot_indi_source) {
+        if ($tot_indi > 0 || $tot_indi_source > 0) {
             $data[] = [
                 I18N::translate('Without sources'),
                 $tot_indi - $tot_indi_source
diff --git a/app/Statistics/Google/ChartMortality.php b/app/Statistics/Google/ChartMortality.php
index c997fbcff6..3cfeca5b48 100644
--- a/app/Statistics/Google/ChartMortality.php
+++ b/app/Statistics/Google/ChartMortality.php
@@ -66,7 +66,7 @@ class ChartMortality
             ]
         ];
 
-        if ($tot_l || $tot_d) {
+        if ($tot_l > 0 || $tot_d > 0) {
             $data[] = [
                 I18N::translate('Living'),
                 $tot_l
diff --git a/app/Statistics/Google/ChartNoChildrenFamilies.php b/app/Statistics/Google/ChartNoChildrenFamilies.php
index 305a967b2f..7e848aa096 100644
--- a/app/Statistics/Google/ChartNoChildrenFamilies.php
+++ b/app/Statistics/Google/ChartNoChildrenFamilies.php
@@ -109,7 +109,7 @@ class ChartNoChildrenFamilies
             ];
         }
 
-        if ($total) {
+        if ($total > 0) {
             $data[] = [
                 I18N::translateContext('unknown century', 'Unknown'),
                 $no_child_fam - $total,
diff --git a/app/Statistics/Google/ChartSex.php b/app/Statistics/Google/ChartSex.php
index abff9e7b4f..a34a680593 100644
--- a/app/Statistics/Google/ChartSex.php
+++ b/app/Statistics/Google/ChartSex.php
@@ -57,7 +57,7 @@ class ChartSex
             ],
         ];
 
-        if ($tot_m || $tot_f || $tot_u) {
+        if ($tot_m > 0 || $tot_f > 0 || $tot_u > 0) {
             $data[] = [
                 I18N::translate('Males'),
                 $tot_m
diff --git a/app/Statistics/Repository/EventRepository.php b/app/Statistics/Repository/EventRepository.php
index ebbc4cac3e..b0a59fed7d 100644
--- a/app/Statistics/Repository/EventRepository.php
+++ b/app/Statistics/Repository/EventRepository.php
@@ -24,6 +24,7 @@ use Fisharebest\Webtrees\Elements\UnknownElement;
 use Fisharebest\Webtrees\Fact;
 use Fisharebest\Webtrees\Family;
 use Fisharebest\Webtrees\Gedcom;
+use Fisharebest\Webtrees\GedcomRecord;
 use Fisharebest\Webtrees\Header;
 use Fisharebest\Webtrees\I18N;
 use Fisharebest\Webtrees\Individual;
@@ -243,10 +244,10 @@ class EventRepository implements EventRepositoryInterface
         $row    = $this->eventQuery($direction);
         $result = I18N::translate('This information is not available.');
 
-        if ($row) {
+        if ($row !== null) {
             $record = Registry::gedcomRecordFactory()->make($row->id, $this->tree);
 
-            if ($record && $record->canShow()) {
+            if ($record instanceof GedcomRecord && $record->canShow()) {
                 $result = $record->formatList();
             } else {
                 $result = I18N::translate('This information is private and cannot be shown.');
@@ -283,7 +284,7 @@ class EventRepository implements EventRepositoryInterface
     {
         $row = $this->eventQuery($direction);
 
-        if (!$row) {
+        if ($row === null) {
             return '';
         }
 
@@ -360,10 +361,10 @@ class EventRepository implements EventRepositoryInterface
     {
         $row = $this->eventQuery($direction);
 
-        if ($row) {
+        if ($row !== null) {
             $record = Registry::gedcomRecordFactory()->make($row->id, $this->tree);
 
-            if ($record) {
+            if ($record instanceof GedcomRecord) {
                 return '<a href="' . e($record->url()) . '">' . $record->fullName() . '</a>';
             }
         }
@@ -398,11 +399,11 @@ class EventRepository implements EventRepositoryInterface
     {
         $row = $this->eventQuery($direction);
 
-        if ($row) {
+        if ($row !== null) {
             $record = Registry::gedcomRecordFactory()->make($row->id, $this->tree);
             $fact   = null;
 
-            if ($record) {
+            if ($record instanceof GedcomRecord) {
                 $fact = $record->facts([$row->fact])->first();
             }
 
diff --git a/app/Statistics/Repository/FamilyDatesRepository.php b/app/Statistics/Repository/FamilyDatesRepository.php
index 462a683040..fe69e8b58d 100644
--- a/app/Statistics/Repository/FamilyDatesRepository.php
+++ b/app/Statistics/Repository/FamilyDatesRepository.php
@@ -21,6 +21,7 @@ namespace Fisharebest\Webtrees\Statistics\Repository;
 
 use Fisharebest\Webtrees\Date;
 use Fisharebest\Webtrees\Fact;
+use Fisharebest\Webtrees\GedcomRecord;
 use Fisharebest\Webtrees\I18N;
 use Fisharebest\Webtrees\Registry;
 use Fisharebest\Webtrees\Statistics\Repository\Interfaces\FamilyDatesRepositoryInterface;
@@ -97,10 +98,10 @@ class FamilyDatesRepository implements FamilyDatesRepositoryInterface
         $row    = $this->eventQuery($type, $operation);
         $result = I18N::translate('This information is not available.');
 
-        if ($row) {
+        if ($row !== null) {
             $record = Registry::gedcomRecordFactory()->make($row->id, $this->tree);
 
-            if ($record && $record->canShow()) {
+            if ($record instanceof GedcomRecord && $record->canShow()) {
                 $result = $record->formatList();
             } else {
                 $result = I18N::translate('This information is private and cannot be shown.');
@@ -186,7 +187,7 @@ class FamilyDatesRepository implements FamilyDatesRepositoryInterface
     {
         $row = $this->eventQuery($type, $operation);
 
-        if (!$row) {
+        if ($row === null) {
             return '';
         }
 
@@ -274,10 +275,10 @@ class FamilyDatesRepository implements FamilyDatesRepositoryInterface
     {
         $row = $this->eventQuery($type, $operation);
 
-        if ($row) {
+        if ($row !== null) {
             $record = Registry::gedcomRecordFactory()->make($row->id, $this->tree);
 
-            if ($record) {
+            if ($record instanceof GedcomRecord) {
                 return '<a href="' . e($record->url()) . '">' . $record->fullName() . '</a>';
             }
         }
@@ -361,11 +362,11 @@ class FamilyDatesRepository implements FamilyDatesRepositoryInterface
     {
         $row = $this->eventQuery($type, $operation);
 
-        if ($row) {
+        if ($row != null) {
             $record = Registry::gedcomRecordFactory()->make($row->id, $this->tree);
             $fact   = null;
 
-            if ($record) {
+            if ($record instanceof GedcomRecord) {
                 $fact = $record->facts([$row->fact])->first();
             }
 
diff --git a/app/Statistics/Repository/FamilyRepository.php b/app/Statistics/Repository/FamilyRepository.php
index 7b88261e04..7a6d397b10 100644
--- a/app/Statistics/Repository/FamilyRepository.php
+++ b/app/Statistics/Repository/FamilyRepository.php
@@ -1128,7 +1128,12 @@ class FamilyRepository
             $husb = $family->husband();
             $wife = $family->wife();
 
-            if ($husb && ($husb->getAllDeathDates() || !$husb->isDead()) && $wife && ($wife->getAllDeathDates() || !$wife->isDead())) {
+            if (
+                $husb instanceof Individual &&
+                $wife instanceof Individual &&
+                ($husb->getAllDeathDates() || !$husb->isDead()) &&
+                ($wife->getAllDeathDates() || !$wife->isDead())
+            ) {
                 if ($family->canShow()) {
                     if ($type === 'list') {
                         $top10[] = '<li><a href="' . e($family->url()) . '">' . $family->fullName() . '</a> (' . $age . ')' . '</li>';
diff --git a/app/Statistics/Repository/HitCountRepository.php b/app/Statistics/Repository/HitCountRepository.php
index 1075659e47..656a44b025 100644
--- a/app/Statistics/Repository/HitCountRepository.php
+++ b/app/Statistics/Repository/HitCountRepository.php
@@ -20,6 +20,7 @@ declare(strict_types=1);
 namespace Fisharebest\Webtrees\Statistics\Repository;
 
 use Fisharebest\Webtrees\Auth;
+use Fisharebest\Webtrees\Contracts\UserInterface;
 use Fisharebest\Webtrees\Services\UserService;
 use Fisharebest\Webtrees\Statistics\Repository\Interfaces\HitCountRepositoryInterface;
 use Fisharebest\Webtrees\Tree;
@@ -63,7 +64,7 @@ class HitCountRepository implements HitCountRepositoryInterface
         } elseif ($page_name === 'index.php') {
             // index.php?context=user
             $user           = $this->user_service->findByIdentifier($page_parameter);
-            $page_parameter = 'user:' . ($user ? $user->id() : Auth::id());
+            $page_parameter = 'user:' . ($user instanceof UserInterface ? $user->id() : Auth::id());
         }
 
         $count = (int) DB::table('hit_counter')
diff --git a/app/Statistics/Repository/IndividualRepository.php b/app/Statistics/Repository/IndividualRepository.php
index 9224110cba..73989656c6 100644
--- a/app/Statistics/Repository/IndividualRepository.php
+++ b/app/Statistics/Repository/IndividualRepository.php
@@ -135,7 +135,7 @@ class IndividualRepository implements IndividualRepositoryInterface
             // Split “John Thomas” into “John” and “Thomas” and count against both totals
             foreach (explode(' ', (string) $n_givn) as $given) {
                 // Exclude initials and particles.
-                if (!preg_match('/^([A-Z]|[a-z]{1,3})$/', $given)) {
+                if (preg_match('/^([A-Z]|[a-z]{1,3})$/', $given) !== 1) {
                     if (array_key_exists($given, $nameList)) {
                         $nameList[$given] += (int) $count;
                     } else {
diff --git a/app/Statistics/Repository/LatestUserRepository.php b/app/Statistics/Repository/LatestUserRepository.php
index 622adb9541..a3663e74ad 100644
--- a/app/Statistics/Repository/LatestUserRepository.php
+++ b/app/Statistics/Repository/LatestUserRepository.php
@@ -151,6 +151,6 @@ class LatestUserRepository implements LatestUserRepositoryInterface
             ->where('user_id', '=', $user->id())
             ->first();
 
-        return $is_logged_in ? $yes : $no;
+        return $is_logged_in !== null ? $yes : $no;
     }
 }
diff --git a/app/Statistics/Repository/PlaceRepository.php b/app/Statistics/Repository/PlaceRepository.php
index 2c108fbd77..ef1917771b 100644
--- a/app/Statistics/Repository/PlaceRepository.php
+++ b/app/Statistics/Repository/PlaceRepository.php
@@ -91,7 +91,7 @@ class PlaceRepository implements PlaceRepositoryInterface
         $placelist = [];
 
         foreach ($rows as $row) {
-            if (preg_match('/\n1 ' . $fact . '(?:\n[2-9].*)*\n2 PLAC (.+)/', $row->tree, $match)) {
+            if (preg_match('/\n1 ' . $fact . '(?:\n[2-9].*)*\n2 PLAC (.+)/', $row->tree, $match) === 1) {
                 $place = $match[1];
 
                 $placelist[$place] = ($placelist[$place] ?? 0) + 1;
diff --git a/app/Statistics/Repository/UserRepository.php b/app/Statistics/Repository/UserRepository.php
index ba41ff5688..9a3439a08f 100644
--- a/app/Statistics/Repository/UserRepository.php
+++ b/app/Statistics/Repository/UserRepository.php
@@ -86,7 +86,7 @@ class UserRepository implements UserRepositoryInterface
         }
 
         if ($count_logged_in > 0) {
-            if ($anonymous) {
+            if ($anonymous !== 0) {
                 if ($type === 'list') {
                     $content .= '<br><br>';
                 } else {
diff --git a/app/Statistics/Service/ColorService.php b/app/Statistics/Service/ColorService.php
index 0dc3d84c82..4cb4b22eeb 100644
--- a/app/Statistics/Service/ColorService.php
+++ b/app/Statistics/Service/ColorService.php
@@ -41,7 +41,7 @@ class ColorService
      */
     public function interpolateRgb(string $startColor, string $endColor, int $steps): array
     {
-        if (!$steps) {
+        if ($steps === 0) {
             return [];
         }
 
diff --git a/app/SurnameTradition/IcelandicSurnameTradition.php b/app/SurnameTradition/IcelandicSurnameTradition.php
index b5ba309039..a371d9149c 100644
--- a/app/SurnameTradition/IcelandicSurnameTradition.php
+++ b/app/SurnameTradition/IcelandicSurnameTradition.php
@@ -73,7 +73,7 @@ class IcelandicSurnameTradition extends DefaultSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_GIVN, $this->extractName($father), $match)) {
+        if (preg_match(self::REGEX_GIVN, $this->extractName($father), $match) === 1) {
             switch ($sex) {
                 case 'M':
                     $givn = $match['GIVN'] . 'sson';
@@ -106,13 +106,13 @@ class IcelandicSurnameTradition extends DefaultSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if ($sex === 'M' && preg_match('~(?<GIVN>[^ /]+)(:?sson)$~', $this->extractName($child), $match)) {
+        if ($sex === 'M' && preg_match('~(?<GIVN>[^ /]+)(:?sson)$~', $this->extractName($child), $match) === 1) {
             return [
                 $this->buildName($match['GIVN'], ['TYPE' => NameType::VALUE_BIRTH, 'GIVN' => $match['GIVN']]),
             ];
         }
 
-        if ($sex === 'F' && preg_match('~(?<GIVN>[^ /]+)(:?sdottir)$~', $this->extractName($child), $match)) {
+        if ($sex === 'F' && preg_match('~(?<GIVN>[^ /]+)(:?sdottir)$~', $this->extractName($child), $match) === 1) {
             return [
                 $this->buildName($match['GIVN'], ['TYPE' => NameType::VALUE_BIRTH, 'GIVN' => $match['GIVN']]),
             ];
diff --git a/app/SurnameTradition/LithuanianSurnameTradition.php b/app/SurnameTradition/LithuanianSurnameTradition.php
index ed1afa2e6a..9adbce8e73 100644
--- a/app/SurnameTradition/LithuanianSurnameTradition.php
+++ b/app/SurnameTradition/LithuanianSurnameTradition.php
@@ -89,7 +89,7 @@ class LithuanianSurnameTradition extends PaternalSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_SURN, $this->extractName($father), $match)) {
+        if (preg_match(self::REGEX_SURN, $this->extractName($father), $match) === 1) {
             if ($sex === 'F') {
                 $name = $this->inflect($match['NAME'], self::INFLECT_DAUGHTER);
                 $surn = $this->inflect($match['SURN'], self::INFLECT_MALE);
@@ -118,7 +118,7 @@ class LithuanianSurnameTradition extends PaternalSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if ($sex === 'M' && preg_match(self::REGEX_SURN, $this->extractName($child), $match)) {
+        if ($sex === 'M' && preg_match(self::REGEX_SURN, $this->extractName($child), $match) === 1) {
             $name = $this->inflect($match['NAME'], self::INFLECT_MALE);
             $surn = $this->inflect($match['SURN'], self::INFLECT_MALE);
 
@@ -142,7 +142,7 @@ class LithuanianSurnameTradition extends PaternalSurnameTradition
      */
     public function newSpouseNames(Individual $spouse, string $sex): array
     {
-        if ($sex === 'F' && preg_match(self::REGEX_SURN, $this->extractName($spouse), $match)) {
+        if ($sex === 'F' && preg_match(self::REGEX_SURN, $this->extractName($spouse), $match) === 1) {
             $name = $this->inflect($match['NAME'], self::INFLECT_WIFE);
             $surn = $this->inflect($match['SURN'], self::INFLECT_MALE);
 
diff --git a/app/SurnameTradition/MatrilinealSurnameTradition.php b/app/SurnameTradition/MatrilinealSurnameTradition.php
index 3b3560f6a6..c73fd647e6 100644
--- a/app/SurnameTradition/MatrilinealSurnameTradition.php
+++ b/app/SurnameTradition/MatrilinealSurnameTradition.php
@@ -61,7 +61,7 @@ class MatrilinealSurnameTradition extends DefaultSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_SPFX_SURN, $this->extractName($mother), $match)) {
+        if (preg_match(self::REGEX_SPFX_SURN, $this->extractName($mother), $match) === 1) {
             $name = $match['NAME'];
             $spfx = $match['SPFX'];
             $surn = $match['SURN'];
@@ -84,7 +84,7 @@ class MatrilinealSurnameTradition extends DefaultSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if ($sex === 'F' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($child), $match)) {
+        if ($sex === 'F' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($child), $match) === 1) {
             $name = $match['NAME'];
             $spfx = $match['SPFX'];
             $surn = $match['SURN'];
diff --git a/app/SurnameTradition/PaternalSurnameTradition.php b/app/SurnameTradition/PaternalSurnameTradition.php
index 22896ff385..51a459fa35 100644
--- a/app/SurnameTradition/PaternalSurnameTradition.php
+++ b/app/SurnameTradition/PaternalSurnameTradition.php
@@ -61,7 +61,7 @@ class PaternalSurnameTradition extends PatrilinealSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if ($sex === 'F' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($child), $match)) {
+        if ($sex === 'F' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($child), $match) === 1) {
             $name = $match['NAME'];
             $spfx = $match['SPFX'];
             $surn = $match['SURN'];
@@ -85,7 +85,7 @@ class PaternalSurnameTradition extends PatrilinealSurnameTradition
      */
     public function newSpouseNames(Individual $spouse, string $sex): array
     {
-        if ($sex === 'F' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($spouse), $match)) {
+        if ($sex === 'F' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($spouse), $match) === 1) {
             $name = $match['NAME'];
             $spfx = $match['SPFX'];
             $surn = $match['SURN'];
diff --git a/app/SurnameTradition/PatrilinealSurnameTradition.php b/app/SurnameTradition/PatrilinealSurnameTradition.php
index 098f05de3a..fa1c7ce49e 100644
--- a/app/SurnameTradition/PatrilinealSurnameTradition.php
+++ b/app/SurnameTradition/PatrilinealSurnameTradition.php
@@ -61,7 +61,7 @@ class PatrilinealSurnameTradition extends DefaultSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_SPFX_SURN, $this->extractName($father), $match)) {
+        if (preg_match(self::REGEX_SPFX_SURN, $this->extractName($father), $match) === 1) {
             $name = $match['NAME'];
             $spfx = $match['SPFX'];
             $surn = $match['SURN'];
@@ -84,7 +84,7 @@ class PatrilinealSurnameTradition extends DefaultSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if ($sex === 'M' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($child), $match)) {
+        if ($sex === 'M' && preg_match(self::REGEX_SPFX_SURN, $this->extractName($child), $match) === 1) {
             $name = $match['NAME'];
             $spfx = $match['SPFX'];
             $surn = $match['SURN'];
diff --git a/app/SurnameTradition/PolishSurnameTradition.php b/app/SurnameTradition/PolishSurnameTradition.php
index 05be7a6c74..7ebc96ee3d 100644
--- a/app/SurnameTradition/PolishSurnameTradition.php
+++ b/app/SurnameTradition/PolishSurnameTradition.php
@@ -79,7 +79,7 @@ class PolishSurnameTradition extends PaternalSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_SURN, $this->extractName($father), $match)) {
+        if (preg_match(self::REGEX_SURN, $this->extractName($father), $match) === 1) {
             if ($sex === 'F') {
                 $name = $this->inflect($match['NAME'], self::INFLECT_FEMALE);
             } else {
@@ -104,7 +104,7 @@ class PolishSurnameTradition extends PaternalSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if ($sex === 'M' && preg_match(self::REGEX_SURN, $this->extractName($child), $match)) {
+        if ($sex === 'M' && preg_match(self::REGEX_SURN, $this->extractName($child), $match) === 1) {
             $name = $this->inflect($match['NAME'], self::INFLECT_MALE);
             $surn = $this->inflect($match['SURN'], self::INFLECT_MALE);
 
@@ -126,7 +126,7 @@ class PolishSurnameTradition extends PaternalSurnameTradition
      */
     public function newSpouseNames(Individual $spouse, string $sex): array
     {
-        if ($sex === 'F' && preg_match(self::REGEX_SURN, $this->extractName($spouse), $match)) {
+        if ($sex === 'F' && preg_match(self::REGEX_SURN, $this->extractName($spouse), $match) === 1) {
             $name = $this->inflect($match['NAME'], self::INFLECT_FEMALE);
             $surn = $this->inflect($match['SURN'], self::INFLECT_MALE);
 
diff --git a/app/SurnameTradition/PortugueseSurnameTradition.php b/app/SurnameTradition/PortugueseSurnameTradition.php
index 937d4d5ea9..bb962d1a69 100644
--- a/app/SurnameTradition/PortugueseSurnameTradition.php
+++ b/app/SurnameTradition/PortugueseSurnameTradition.php
@@ -74,13 +74,13 @@ class PortugueseSurnameTradition extends DefaultSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_SURNS, $this->extractName($father), $match_father)) {
+        if (preg_match(self::REGEX_SURNS, $this->extractName($father), $match_father) === 1) {
             $father_surname = $match_father['SURN2'];
         } else {
             $father_surname = '';
         }
 
-        if (preg_match(self::REGEX_SURNS, $this->extractName($mother), $match_mother)) {
+        if (preg_match(self::REGEX_SURNS, $this->extractName($mother), $match_mother) === 1) {
             $mother_surname = $match_mother['SURN2'];
         } else {
             $mother_surname = '';
@@ -104,7 +104,7 @@ class PortugueseSurnameTradition extends DefaultSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if (preg_match(self::REGEX_SURNS, $this->extractName($child), $match)) {
+        if (preg_match(self::REGEX_SURNS, $this->extractName($child), $match) === 1) {
             switch ($sex) {
                 case 'M':
                     return [
diff --git a/app/SurnameTradition/SpanishSurnameTradition.php b/app/SurnameTradition/SpanishSurnameTradition.php
index 6318f09307..ddb1163cc9 100644
--- a/app/SurnameTradition/SpanishSurnameTradition.php
+++ b/app/SurnameTradition/SpanishSurnameTradition.php
@@ -74,13 +74,13 @@ class SpanishSurnameTradition extends DefaultSurnameTradition
      */
     public function newChildNames(?Individual $father, ?Individual $mother, string $sex): array
     {
-        if (preg_match(self::REGEX_SURNS, $this->extractName($father), $match_father)) {
+        if (preg_match(self::REGEX_SURNS, $this->extractName($father), $match_father) === 1) {
             $father_surname = $match_father['SURN1'];
         } else {
             $father_surname = '';
         }
 
-        if (preg_match(self::REGEX_SURNS, $this->extractName($mother), $match_mother)) {
+        if (preg_match(self::REGEX_SURNS, $this->extractName($mother), $match_mother) === 1) {
             $mother_surname = $match_mother['SURN1'];
         } else {
             $mother_surname = '';
@@ -104,7 +104,7 @@ class SpanishSurnameTradition extends DefaultSurnameTradition
      */
     public function newParentNames(Individual $child, string $sex): array
     {
-        if (preg_match(self::REGEX_SURNS, $this->extractName($child), $match)) {
+        if (preg_match(self::REGEX_SURNS, $this->extractName($child), $match) === 1) {
             switch ($sex) {
                 case 'M':
                     return [
diff --git a/app/Tree.php b/app/Tree.php
index 9026e2a941..cc85f53f38 100644
--- a/app/Tree.php
+++ b/app/Tree.php
@@ -362,7 +362,7 @@ class Tree
      */
     public function createRecord(string $gedcom): GedcomRecord
     {
-        if (!preg_match('/^0 @@ ([_A-Z]+)/', $gedcom, $match)) {
+        if (preg_match('/^0 @@ ([_A-Z]+)/', $gedcom, $match) !== 1) {
             throw new InvalidArgumentException('GedcomRecord::createRecord(' . $gedcom . ') does not begin 0 @@');
         }
 
diff --git a/app/Validator.php b/app/Validator.php
index 85ac46cc55..ab1a1438b2 100644
--- a/app/Validator.php
+++ b/app/Validator.php
@@ -257,7 +257,7 @@ class Validator
         $value ??= [];
 
         $check_utf8 = static function ($v, $k) use ($parameter) {
-            if (is_string($k) && !preg_match('//u', $k) || is_string($v) && !preg_match('//u', $v)) {
+            if (is_string($k) && preg_match('//u', $k) !== 1 || is_string($v) && preg_match('//u', $v) !== 1) {
                 throw new HttpBadRequestException(I18N::translate('The parameter “%s” is missing.', $parameter));
             }
         };