How to create new object by two objects in javascript

Question

I would like to know how to create new object by two objects in javascript.

iterate through the obj1, and add the obj2 values, create new object in javascript

function getObject(obj1, obj2){
  let result={};
  Object.keys(obj1).forEach(key=>{
    if(key==="start" || key==="end"){
      result.time= obj1.start+"-"+obj1.end,
      result.qty= obj2.qty
    }
  }) 

}

var obj1 ={
  start: "16:01", end: "23:59", totalqty: 1065, totalamount: 8229170
}

var obj2 = {
  qty: 10, 
  amt: 120
}

Expected Output

 {
   time: "16:01-23:59"
   val: 10 // represents obj2.qty,
   totalqty: 1065, 
   totalamount: 8229170,
   price: 120
 }

checkout [Spread syntax ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax) — Moufeed Juboqji, Jul 29 '20 at 08:35

StepUp · Accepted Answer · 2020-07-29T08:48:07.457

You can write a function and get desired properties:

var obj1 ={
  start: "16:01", end: "23:59", totalqty: 1065, totalamount: 8229170
}

var obj2 = {
  qty: 10,
  amt: 120
}

const merge = (obj1, obj2) => {
  return {
    time: obj1.start + '-' + obj1.end,
    val: obj2.qty,
    totalqty: obj1.totalqty,
    totalamount: obj1.totalamount,
    price: obj2.amt
  };
}

console.log(merge(obj1, obj2));

In addition, you can use spread syntax, but it merges all properties:

let obj1 ={
  start: "16:01", end: "23:59", totalqty: 1065, totalamount: 8229170
}

let obj2 = {
  qty: 10, 
  amt: 120
}

let merged = {...obj1, ...obj2};
console.log(merged );

or try to use Object.assign() and it is also merges all properties:

var obj1 ={
  start: "16:01", end: "23:59", totalqty: 1065, totalamount: 8229170
}

var obj2 = {
  qty: 10, 
  amt: 120
}

var result = Object.assign({}, obj1, obj2);
console.log(result);

Read more Object.assign() here.

thanks but please check expected output, its different – ved Jul 29 '20 at 08:39 — ved, Jul 29 '20 at 08:39

score 1 · Answer 2 · answered Jul 29 '20 at 08:39

You could destructure the objects, rename some properties and return a new object.

const
    merge = ({ start, end, totalqty, totalamount }, { qty: val, amt: price }) =>
        ({ time: start + "-" + end, val, totalqty, totalamount, price}),
    obj1 = { start: "16:01", end: "23:59", totalqty: 1065, totalamount: 8229170 },
    obj2 = { qty: 10, amt: 120 };

console.log(merge(obj1, obj2));

How to create new object by two objects in javascript

2 Answers2