How can the existence of array keys be efficiently checked in PHP?

To efficiently check the existence of array keys in PHP, you can use the `array_key_exists()` function. This function takes two parameters - the key you want to check for and the array you want to search. It returns true if the key exists in the array and false otherwise. This provides a simple and efficient way to determine if a specific key is present in an array. 

// Example code to check the existence of array keys in PHP
$myArray = ['key1' => 'value1', 'key2' => 'value2', 'key3' => 'value3'];

if (array_key_exists('key2', $myArray)) {
    echo 'Key exists in the array';
} else {
    echo 'Key does not exist in the array';
}

Keywords

array_keys array_key_exists isset in_array array_flip

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