Object.assign()
Copies enumerable own properties from source objects to a target object.
Syntax
Object.assign(target, ...sources)Parameters
| Name | Type | Required | Description |
|---|---|---|---|
target | object | Yes | The object to copy properties into. It is modified and returned. |
sources | object | No | One or more source objects whose enumerable own properties are copied. |
Returns
object — The modified target object.
Examples
console.log(Object.assign({ a: 1 }, { b: 2 }, { a: 9 }));
Output
{ a: 9, b: 2 }
const copy = Object.assign({}, { x: 1 });
console.log(copy);
Output
{ x: 1 }
Notes
Mutates and returns the target. Performs a shallow copy - nested objects are
shared by reference. Later sources overwrite earlier ones. The spread operator
`{ ...a, ...b }` is a common alternative.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 45 |
| firefox | 34 |
| safari | 9 |
| edge | 12 |
| node | 4.0 |