JS: Object.assign()
Using Object.assign() to copy and merge objects:
Object.assign(target, source);
find one or moresourceobject totargetobject, and returntargetobject
Example:
const target = { a: 1, b: 2 };
const source = { b: 4, c: 5 };
const returnedTarget = Object.assign(target, source);
console.log(target);
// expected output: Object { a: 1, b: 4, c: 5 }
console.log(returnedTarget);
// expected output: Object { a: 1, b: 4, c: 5 }
Clone
var obj = { a: 1 };
var copy = Object.assign({}, obj);
console.log(copy); // { a: 1 }
Deep Clone
For deep cloning, we need to use other alternatives because Object.assign() copies property values. If the source value is a reference to an object, it only copies that reference value.
Merge
var o1 = { a: 1 };
var o2 = { b: 2 };
var o3 = { c: 3 };
var obj = Object.assign(o1, o2, o3);
console.log(obj); // { a: 1, b: 2, c: 3 }
console.log(o1); // { a: 1, b: 2, c: 3 }, target object itself is changed.
Merge with same properties
var o1 = { a: 1, b: 1, c: 1 };
var o2 = { b: 2, c: 2 };
var o3 = { c: 3 };
var obj = Object.assign({}, o1, o2, o3);
console.log(obj); // { a: 1, b: 2, c: 3 }