Object.assign method

The Object.assign method copies the properties and values of an original object, while returning a new object. In the first parameter of the method, we set the target object to which we are copying, and in the second, we specify the objects to be copied.

Syntax

Object.assign(target, objects);

Example

Let's get a new object from the original:

let obj = {'a': 1, 'b': 2, 'c': 3};
let newObj = Object.assign({}, obj);
console.log(newObj);

The code execution result:

{a: 1, b: 2, c: 3}

Example

And now we get a new object from several original ones, listing them in the parameter separated by commas:

let obj1 = {'a': 1, 'b': 2};
let obj2 = {'c': 3, 'd': 4};

let newObj = Object.assign({}, obj1, obj2);
console.log(newObj);

After executing the code, we will see that the two original objects have merged into one new object:

{a: 1, b: 2, c: 3, d: 4}

Example

Also, the Object.assign method can be used to get a new array, since an array, by its type, is also an object. Let's make a new array by copying elements from the original one:

let arr = [1, 2, 3, 4];
let newArr = Object.assign([], arr);

console.log(newArr);

The code execution result:

[1, 2, 3, 4]

Example

When using the Object.assign method, you need to be careful about the syntax. For example, if you do not add the target object to the first parameter, but leave only the copied object, then it will return back:

let obj = {1:'a', 2: 'b', 3: 'c'};
let newObj = Object.assign(obj);

console.log(newObj === obj);

The code execution result:

true

Object.assign method

Syntax

Example

Example

Example

Example

See also