What s quicker and better to determine if an array key exists in PHP

Question

$key = 'jim';

// example 1
if (isset($array[$key])) {
    // ...
}

// example 2    
if (array_key_exists($key, $array)) {
    // ...
}

Out of these two examples which one is a better option? I usually use the first one but I have seen people using the second one more. So can someone please tell me which one is a better option?

Answer 1

array_key_exists() -  purely checks if the key exists, even if the value is NULL.

Whereas isset() -  will return false if the key exists and the value is NULL.

isset() is faster, but it's not the same as array_key_exists(). 

I hope this helps you.