Associative arrays in JavaScript

The so-called associative array (associative array) refers to objects in JavaScript.

Because a property in JavaScript is a key-value pair that can be accessed through obj[attr], it is similar to an array.

There are many other types of data structures:

Hash (hash)

Hash table (Hashtable)

Dictionary (dictionary)

The most confusing thing is that arrays in JavaScript can also use non-numeric storage values, such as:

var arr = [];

arr[' uname '] = ' uname ';

But the value added in this way does not affect his array attributes. The length of this array is still 0.

In fact, this is because objects such as arrays inherit object, so they also have basic properties of the object, and can store key-value pairs.

Not only an array, but all the other objects are available.

Associative arrays in JavaScript