How to Insert Elements at the Beginning of a PHP Array with array_unshift

PHP is a widely used server‑side scripting language, and arrays are a core data structure for storing collections of values. When you need to prepend elements to an array, the built‑in array_unshift function is the most convenient tool.

The function inserts one or more values at the beginning of an array and returns the new number of elements. Its syntax is:

array_unshift(array $array, mixed $value1 [, mixed $value2 ...])

Here $array is the target array, and $value1, $value2, etc., are the values to prepend.

Example 1: Adding a fruit to a list

<?php
$fruits = array("apple", "orange", "banana");

echo "Before array_unshift: ";
print_r($fruits);

array_unshift($fruits, "grape");

echo "After array_unshift: ";
print_r($fruits);
?>

Running this script produces:

Before array_unshift: Array
(
    [0] => apple
    [1] => orange
    [2] => banana
)
After array_unshift: Array
(
    [0] => grape
    [1] => apple
    [2] => orange
    [3] => banana
)

The original array contained three fruits; after calling array_unshift, "grape" appears at index 0, shifting the existing elements forward.

Example 2: Prepending multiple numbers

<?php
$numbers = array(3, 4, 5);

echo "Before array_unshift: ";
print_r($numbers);

array_unshift($numbers, 1, 2);

echo "After array_unshift: ";
print_r($numbers);
?>

The output is:

Before array_unshift: Array
(
    [0] => 3
    [1] => 4
    [2] => 5
)
After array_unshift: Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

This demonstrates that array_unshift can add several values at once, placing them in the order provided.

In summary, array_unshift offers a simple way to prepend one or more elements to a PHP array without manually re‑indexing, making it useful for a variety of backend programming tasks.