What is Associative Array in JavaScript

In JavaScript, there isn't a distinct data structure referred to as an "associative array." Instead, developers often use objects to achieve similar functionality.

Key-value pairs

Objects in JavaScript are collections of key-value pairs, where the keys (also called property names) are strings and the values can be of any data type. This allows you to create data structures that resemble associative arrays found in other programming languages.

Here's how you can create and use an associative-like structure using objects in JavaScript:

// Creating an "associative array" using an object const person = { name: "Hary", age: 30, occupation: "Engineer" }; // Accessing values using keys console.log(person.name); // Outputs: Hary console.log(person["age"]); // Outputs: 30 // Adding new key-value pairs person.city = "New York"; // Modifying existing values person.age = 32; // Deleting a key-value pair delete person.occupation; // Looping through the "associative array" for (const key in person) { console.log(key, person[key]); }

In this example, the person object serves as an associative-like array, where the keys ("name," "age," "occupation," etc.) are used to access corresponding values. You can add, modify, and delete properties dynamically. The for...in loop allows you to iterate through the keys and access their associated values.


While JavaScript objects provide similar functionality to associative arrays, it's important to note that objects also inherit various properties and methods from their prototypes, which might introduce unexpected behavior. If you need a more specialized structure for mapping keys to values, you might consider using the Map data structure introduced in ECMAScript 6.