Undefined array key php

Warning: Undefined array key 1

return $table[$key] ?? null;

Source: stackoverflow.com

Php get array key

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name = current($array)) {
    if ($fruit_name == 'apple') {
        echo key($array).'<br />';
    }
    next($array);
}
?>

Source: php.net

Keys of array exist in array

function findKey($array, $keySearch)
{
    foreach ($array as $key => $item) {
        if ($key == $keySearch) {
            echo 'yes, it exists';
            return true;
        } elseif (is_array($item) && findKey($item, $keySearch)) {
            return true;
        }
    }
    return false;
}

Source: stackoverflow.com

Undefined array key php

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name = current($array)) {
    if ($fruit_name == 'apple') {
        echo key($array).'<br />';
    }
    next($array);
}
?>

Similar codes

0 vote208 views1 answer
Never return type - PHP 8.1
PHP
0 vote228 views1 answer
Laravel number input positive only
PHP Laravel
0 vote211 views1 answer
Guzzlehttp post json example
PHP
0 vote236 views1 answer
Access to XMLHttpRequest at 'http://localhost/MySQL_pracs/InsertUser.php' from origin 'http://localhost:4200' has been blocked by CORS policy: Request header field content-type is not allowed by Access-Control-Allow-Headers in preflight response.
PHP
2 votes215 views1 answer
Return back in blade laravel
PHP Laravel
12 votes299 views5 answers
Laravel transactions
PHP
0 vote225 views1 answer
Laravel session wont update
PHP
0 vote194 views1 answer
Wordpress remove taxonomy from post
PHP
5 votes230 views6 answers
New laravel 8 project
PHP Laravel
0 vote200 views1 answer
Quitar elemento array php
PHP