Answers for "how to check if key exists in array in php"

php key exists

// Here's our fruity array
$fruits = ['apple', 'pear', 'banana'];

// Use it in an `if` statement
if (array_key_exists("banana", $fruits)) {
 // Do stuff because `banana` exists
}

// Store it for later use
$exists = array_key_exists("peach", $fruits);

php key in array exists

<?php
$search_array = array('first' => null, 'second' => 4);

// returns false
isset($search_array['first']);

// returns true
array_key_exists('first', $search_array);
?>

check array has keys in php

<?php

// The values in this arrays contains the names of the indexes (keys) 
// that should exist in the data array
$required = array('key1', 'key2', 'key3');

$data = array(
    'key1' => 10,
    'key2' => 20,
    'key3' => 30,
    'key4' => 40,
);

if (count(array_intersect_key(array_flip($required), $data)) === count($required)) {
    // All required keys exist!
}