How to Use PHP's array_unshift() to Prepend Elements to an Array

In PHP, arrays are a common data type that can store a series of values and be accessed by index.

Syntax of array_unshift()

The function array_unshift() adds one or more elements to the beginning of an array and returns the new number of elements. Its syntax is: array_unshift(array, value1, value2, ...) In this syntax, array is the target array, and value1, value2, etc., are the values to prepend. The function modifies the original array.

Usage Example

First create an array: $fruits = array("apple", "banana", "cherry"); Then prepend a new element: array_unshift($fruits, "orange"); After the call, $fruits becomes: array("orange", "apple", "banana", "cherry"); You can also prepend multiple values at once: array_unshift($fruits, "pear", "grape"); Resulting in:

array("pear", "grape", "orange", "apple", "banana", "cherry");

The function accepts values of any type, such as integers, floats, or booleans.

It can also prepend another array, making that array the first element:

$more_fruits = array("melon", "kiwi");
array_unshift($fruits, $more_fruits);

Now $fruits starts with the nested array:

array(array("melon", "kiwi"), "pear", "grape", "orange", "apple", "banana", "cherry");

Typical use cases include inserting a new product at the beginning of a shopping‑cart list or adding a newly published article to the top of a blog feed.

Precautions

Because array_unshift() modifies the original array, it is advisable to back up the array before calling the function to avoid accidental data loss.

Conclusion

The array_unshift() function is a practical tool for PHP developers to prepend elements to arrays, making array manipulation more flexible. Remember to back up your data before using it.