New Built-in Classes: Map

Using Map

Associative maps or dictionaries are significant data structures in programming. You may have used Map in Java or Dictionary in C#, for example. Suppose you want to keep track of teams and scores during the sports season.

Why were maps introduced in JavaScript?

A map will make it easy to create and update the score values and also to look up the scores based on a team’s name. It’s hard to believe that we can seriously program without maps.

Since an object in JavaScript has keys and values and there was no special Map type, programmers often used ...