Using unset() function: The unset() function is used to unset a key and its value in an associative array in php.

1. Code:

<?php
// Declare an associative array
$arr = array( 
    "1" => "Soltuts",
    "2" => "sol",
    "3" => "Divide"
);
  
// Remove the key 1 and its value
// from associative array
unset($arr['3']);
  
// Display the array elements
print_r($arr);
?>

2. Example:

Input:

Array( 
    "1" => "Soltuts",
    "2" => "sol",
    "3" => "Divide"
);

Output:

Array ( 
[1] => Soltuts
 [2] => sol
 )