How to check if an array contains a specific key in PHP?

To check if an array contains a specific key in PHP, you can use the array_key_exists() function. This function checks if a given key or index exists in an array.

Here's an example of how to use array_key_exists() function to check if an array contains a specific key:

<?php
$array = array(
  "name" => "John",
  "age" => 25,
  "city" => "New York"
);

if (array_key_exists("name", $array)) {
  echo "The key 'name' exists!";
} else {
  echo "The key 'name' does not exist!";
}
?>

In this example, the array_key_exists() function is used to check if the key 'name' exists in the $array. If it does, it will display "The key 'name' exists!"; otherwise, it will display "The key 'name' does not exist!".

Note that array_key_exists() will return true even if the value associated with the key is null. If you want to check if the value is null, you can use isset().