problem with unset in 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: Deleting an element from an array in PHP

$array = [0 => "a", 1 => "b", 2 => "c"];
unset($array[1]); //Key which you want to delete
/*
$array:
[
    [0] => a
    [2] => c
]
*/
//OR
$array = [0 => "a", 1 => "b", 2 => "c"];
array_splice($array, 1, 1);//Offset which you want to delet
/*
$array:
[
    [0] => a
    [1] => c
]
*/