js best way to merge an object into itself code example

Example 1: how to merge two objects into one in javascript

let obj1 = { foo: 'bar', x: 42 };
let obj2 = { foo: 'baz', y: 13 };

let clonedObj = { ...obj1 };
// Object { foo: "bar", x: 42 }

let mergedObj = { ...obj1, ...obj2 };
// Object { foo: "baz", x: 42, y: 13 }

Example 2: two object combine together javascript

const a = { b: 1, c: 2 };
const d = { e: 1, f: 2 };

const ad = { ...a, ...d }; // { b: 1, c: 2, e: 1, f: 2 }


let objs = [{firstName: "Steven"}, {lastName: "Hancock"}, {score: 85}];

let obj = objs.reduce(function(acc, val) {
    return Object.assign(acc, val);
},{});