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 vote236 views2 answers
Optimize wordpress query
PHP
0 vote274 views1 answer
The Process class relies on proc_open, which is not available on your PHP installation cpanel
PHP
8 votes226 views6 answers
Php isset
PHP
19 votes245 views2 answers
PHP auto refresh page
PHP
0 vote247 views1 answer
Finding second highest number in array
PHP
5 votes239 views4 answers
Php get time in milliseconds
PHP
0 vote237 views3 answers
Php command get ini params
PHP
0 vote242 views1 answer
Die laravel
PHP
0 vote274 views1 answer
Custom pagination laravel css
PHP Laravel
10 votes218 views2 answers
Php post request
PHP