I have two types of array 1. Indexed arrays and 2. Associative Array. I need help to check key exists in an array or not.

1. Indexed arrays

$index_array = ['apple', 'pear', 'banana'];

2. Associative Array

$associative_array= array('first' => null, 'second' => 4);

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

I am interested in knowing if either of these is better. I have always used the first, but have seen a lot of people use the second example on this site.

So, which is better? Faster? Clearer intent?

php array 
1 Answers

If you are interested in some tests I've done recently:

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

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 value is NULL.


1. Indexed arrays

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

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

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

// Return it directly
return array_key_exists("pineapple", $index_array);


2: Associative Array

$associative_array= array('first' => null, 'second' => 4);

// returns false

// returns true
array_key_exists('first', $associative_array);


answered Nov 26

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