Object literal

JavaScriptJunior~1 min read

an object literal is the simplest and most common way to create an object in JavaScript.

It is used when you describe an object directly "in place", using curly braces {}.

Short answer

An object literal is an expression of the form:

javascript

const user = {
  name: 'Tim',
  age: 25,
  city: 'Kyiv'
};

Here:

A "literal" is a value written directly in the code, rather than created through a constructor or function.

For example:

So an "object literal" is simply declaring an object directly via {}.

javascript

const user = {
  name: 'Tim',
  age: 25,
  sayHi() {
    console.log(`Hi, ${this.name}!`);
  }
};

user.sayHi(); // "Hi, Tim!"

An object literal can hold not only data but also functions (methods) that work with that data.

You can use variables as keys:

javascript

const key = 'email';
const user = {
  name: 'Tim',
  [key]: 'tim@mail.com'
};

console.log(user.email); // "tim@mail.com"

The [] brackets let you set a dynamic property name when the object is created.

If the variable name matches the key, you can write it more concisely:

javascript

const name = 'Tim';
const age = 25;

const user = { name, age };

console.log(user); // { name: 'Tim', age: 25 }

Here name: name automatically shortens to just name.

Way	Example	Note
Object literal	`{ name: 'Tim' }`	the simplest and most popular
`new Object()`	`const obj = new Object();`	more verbose syntax
`Object.create(proto)`	`Object.create(null)`	used to control the prototype
`class`	`new User()`	the object is created via a class constructor

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