Comparison of programming languages (associative array): Difference between revisions

Revision as of 02:46, 10 December 2023

Revision as of 17:50, 9 January 2024

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====Map and WeakMap====

Modern JavaScript handles associative arrays, using the <code>Map</code> and <code>WeakMap</code> classes. A map does not contain any keys by default; it only contains what is explicitly put into it. The keys and values can be any type (including functions, objects, or any primitive).

=====Creation=====

A map can be initialized with all items during construction:

<syntaxhighlight lang="javascript">

const phoneBook = new Map([

["Sally Smart", "555-9999"],

["John Doe", "555-1212"],

["J. Random Hacker", "553-1337"],

]);

</syntaxhighlight>

Alternatively, you can initialize an empty map and then add items:

<syntaxhighlight lang="javascript">

const phoneBook = new Map();

phoneBook.set("Sally Smart", "555-9999");

phoneBook.set("John Doe", "555-1212");

phoneBook.set("J. Random Hacker", "553-1337");

</syntaxhighlight>

=====Access by key=====