<?php
$array = array('a','b','c','d','e');
unset($array[4]);
print_r($array);
?>
Array
( [0] => a [1] => b [2] => c [3] => d
) 

if (in_array('strawberry', $array))
{ unset($array[array_search('strawberry',$array)]);
}

$items = ['banana', 'apple'];
unset($items[0]);
var_dump($items); // ['apple']

$arr = array('a' => 1, 'b' => 2, 'c' => 3);
unset($arr['b']);
// RESULT: array('a' => 1, 'c' => 3)
$arr = array(1, 2, 3);
array_splice($arr, 1, 1);
// RESULT: array(0 => 1, 1 => 3)

//Delete array items with unset(no re-index) or array_splice(re-index)
$colors = array("red","blue","green");
unset($colors[1]);//remove second element, do not re-index array
$colors = array("red","blue","green");
array_splice($colors, 1, 1); //remove second element, re-index array

$array = [0 => "a", 1 => "b", 2 => "c", 3 => "c"];
$array = array_diff($array, ["a", "c"]);

$arr1 = array( 'geeks', // [0] 'for', // [1] 'geeks' // [2]
);
// remove item at index 1 which is 'for'
unset($arr1[1]);
// Re-index the array elements
$arr2 = array_values($arr1);
// Print re-indexed array
var_dump($arr1);

unset($user[$i]);
// Re-index the array elements
$user = array_values($user);

array_diff( [312, 401, 15, 401, 3], [401] ) // removing 401 returns [312, 15, 3]
// https://stackoverflow.com/questions/7225070/php-array-delete-by-value-not-key#:~:text=with%20one%20element.-,array_diff(%20%5B312%2C%20401%2C%2015%2C%20401%2C%203%5D%2C%20%5B401%5D%20)%20//%20removing%20401%20returns%20%5B312%2C%2015%2C%203%5D,-It%20generalizes%20nicely

$array = [0 => "a", 1 => "b", 2 => "c",3=>"d"];
//Params are: array,index to delete,number of elements to remove
array_splice($array, 2, 1);
//print_r($array);
//Array
//(
// [0] => a
// [1] => b
// [2] => d
//)