Definition and Usage

PHP Version
4+

The array_pop() function removes the last element from an array and returns it.

It effectively deletes that element from the original array.

Features

  • This operation decreases the length of the array by one.
  • Returns the removed element.
  • Modifies the original array directly.

Basic Example

PHP 
$array = ['orange', 'banana', 'apple'];

// Removes the last element from the array
array_pop($array);
print_r($array);
/*
Output:
    Array
    (
        [0] => orange
        [1] => banana
    )
*/

Syntax

PHP 
array_pop(array &$array): mixed

Parameters

Parameters of the array_pop() Function
&$array The target array from which the last element will be removed (passed by reference).

Return Values

The array_pop() function returns the last element removed from the array. If the array is empty and there is no element to remove, it returns null.

PHP Return Value of array_pop() 
// Initialize the array
$array = ['orange', 'banana', 'apple'];

// Remove the last element from the array
$removedItem = array_pop($array);
print_r($array);
/*
Output:
    Array
    (
        [0] => orange
        [1] => banana
    )
*/

echo $removedItem; // Output: 'apple'

// Case 1: Empty array
$emptyArray_1 = [];
$emptyArray_1_removedItem = array_pop($emptyArray_1); // Array is empty, no element to remove

var_dump($emptyArray_1_removedItem); // NULL

// Case 2: Array with one element
$emptyArray_2 = [1];
$emptyArray_2_removedItem = array_pop($emptyArray_2);

var_dump($emptyArray_2_removedItem); // int(1)

Important Notes and Use Cases

There are several key concepts and precautions to keep in mind when using the array_pop() function.

  1. Return Value
  2. Modification of the Original Array and Array Length
  3. Works with Associative Arrays
  4. Reversing an Array Using a Loop
  5. Removing the Last Element with unset()

Return Value

The array_pop() function returns the removed element. You can store the returned value in a variable.

PHP 
$fruits = ['apple', 'banana', 'cherry'];
$removedFruit = array_pop($fruits);
echo $removedFruit; // Outputs: 'cherry'

Modification of the Original Array and Array Length

The array_pop() function modifies the original array. Therefore, when you remove an element, the array changes and its length decreases.

PHP 
$fruits = ['apple', 'banana', 'cherry'];
array_pop($fruits);
echo count($fruits); // Outputs: 2

Works with Associative Arrays

The array_pop() function works not only with indexed arrays but also with associative arrays. Since it removes and returns the last element, it is not restricted by array type.

PHP 
$assocArray = ['name' => 'John', 'age' => 30];
array_pop($assocArray);
print_r($assocArray);
/*
Output:
    Array
    (
        [name] => John
    )
*/

Reversing an Array Using a Loop

You can reverse an array by combining array_pop() with a loop.

PHP 
// Original array
$fruits = ['apple', 'banana', 'cherry'];

// Create an empty array to hold reversed elements
$reversedFruits = [];

// Use a loop to pop elements from the original array and add them to the new array
while ($fruit = array_pop($fruits)) {
    $reversedFruits[] = $fruit;
}

// Output the reversed array
print_r($reversedFruits);
/*
Output:
    Array
    (
        [0] => cherry
        [1] => banana
        [2] => apple
    )
*/

Note that PHP provides a built-in function array_reverse() which reverses arrays more simply and intuitively:

PHP 
$fruits = ['apple', 'banana', 'cherry'];

// Reverse the array
$reversedFruits = array_reverse($fruits);

// Output the reversed array
print_r($reversedFruits);
/*
Output:
    Array
    (
        [0] => cherry
        [1] => banana
        [2] => apple
    )
*/

Removing the Last Element with unset()

Instead of using array_pop(), you can remove the last element of an array using the unset() function. The unset() function removes a specific variable or array element.

PHP 
// Original array
$fruits = ['apple', 'banana', 'cherry'];

// Remove the last element using unset()
unset($fruits[count($fruits) - 1]);

// Output the array
print_r($fruits);
/*
Output:
    Array
    (
        [0] => apple
        [1] => banana
    )
*/

This method is a simple way to remove the last element, but it requires you to first get the array's length.

References

See also