PHP array_key_exists() function

This function is used to check the existence of the given array index in the array. It always returns a boolean value, either TRUE or FALSE.

Syntax

array_key_exists(key_name, array);

Both parameters are required. It returns TRUE if the key exists in the array, otherwise it returns false.

Example1

<?php
    $arr = array( 'BIKE' => 'RED', 'CLOTH'=> 'BLUE', 'PURSE' => 'YELLOW');
    if(array_key_exists('CLOTH', $arr)) {
        echo 'cloth key exists in the array';
    }
    else{
        echo 'cloth key is not existing.';
    }
?>

Example2

<?php
    $arr = array( 'BIKE' => 'RED', 'CLOTH'=> 'BLUE', 'PURSE' => 'YELLOW');
    if(array_key_exists('CYCLE', $arr)) {
        echo 'Cycle key exists in the array';
    }
    else{
        echo 'Cycle key is not existing.';
    }
?>