is unset for the index php code example

Example 1: php delete element by value

$colors = array("blue","green","red");

//delete element in array by value "green"
if (($key = array_search("green", $colors)) !== false) {
    unset($colors[$key]);
}

Example 2: php remove item array

$items = ['banana', 'apple'];

unset($items[0]);

var_dump($items); // ['apple']