PHP Ds\Map Functions Complete Reference

A Map is a sequential collection of key-value pair which is very similar to the array. The key of a map can be of any type and it is unique. If any value added to the same key in a Map then the map value will replace. It is the efficient Data Structure in PHP 7 to provide the alternative of an array. 

Requirements: PHP 7 is required for both extension and the compatibility polyfill.

Installation: The easiest way to install data structure by using PECL extension.

pecl install ds

Syntax:

public Ds\Map::functionName()

Example: Below programs illustrate the Ds\Map::filter() function in PHP:

<?php
// PHP program to illustrate the filter()
// function of Ds\map
// Creating a Map
$map = new \Ds\Map([
    1 => "Welcome",
    2 => "to",
    3 => "Geeks",
    4 => "for",
    5 => "Geeks"]);
            
// Display new sequence using filter function
var_dump($map->filter(function($key, $val) {
    return $key % 3 == 0;
}));
?>

Output:

object(Ds\Map)#3 (1) {
  [0]=>
  object(Ds\Pair)#2 (2) {
    ["key"]=>
    int(3)
    ["value"]=>
    string(5) "Geeks"
  }
}

Complete list of data structure DS\Map: