How to Store and Retrieve Arrays with PHP

Storing and retrieving arrays in PHP can be a common task for various purposes. While there may not be dedicated functions like store_array(), there are efficient and straightforward methods to accomplish this task.

The preferred approach is to use JSON serialization. This method converts arrays into a human-readable format, resulting in smaller file sizes and faster load/save times.

JSON Serialization

JSON (JavaScript Object Notation) serialization provides two key functions:

• **json_encode(): Converts a PHP array into a JSON string.
• **json_decode(): Converts a JSON string back into a PHP array.

Example Code:

To store an array in a file:

$arr1 = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);
file_put_contents("array.json", json_encode($arr1));

To retrieve the array from the file:

$arr2 = json_decode(file_get_contents('array.json'), true);
$arr1 === $arr2 # => true

Speed Comparison

JSON serialization outperforms other methods in terms of speed:

json_encode($arr1); // 0.000002 seconds
serialize($arr1); // 0.000003 seconds

Custom Functions

You can write your own store_array() and restore_array() functions using the JSON serialization approach:

function store_array($arr, $file) {
    file_put_contents($file, json_encode($arr));
}

function restore_array($file) {
    return json_decode(file_get_contents($file), true);
}

With these functions, you can conveniently store and retrieve arrays with minimal effort. Keep in mind that JSON serialization is not suitable for storing serialized objects or resources, as these cannot be encoded into JSON format.