php unset array key

unset($dataArray['key']);

$array = [0 => "a", 1 => "b", 2 => "c"];
unset($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
]
*/

$arr = array('G', 'E', 'E', 'K', 'S');  
unset($arr[2]);
print_r($arr);

<?php

  $a = "Hello world!";
echo 
  "The value of variable 'a' before unset: " . $a . "<br>";

  unset($a);
echo 
  "The value of variable 'a' after unset: " . $a;
?>