How to push elements of an object into another object?

Question

Like in arrays we can add new elements by using array.push(item). How to do the same with objects? And can it be done inside the object? Like:

var myObject={apple: "a", orange: "o"};
var anothObject = {lemon: "l", myObject};

Answer 1

To copy all elements of one object to another object, use Object.assign:

var myObject = { apple: "a", orange: "o" };
var anothObject = Object.assign( { lemon: "l" }, myObject );

Or, more elegantly ES6 style using spread ... operator:

let myObject = { apple: "a", orange: "o" };
let anothObject = { lemon: "l", ...myObject };

Answer 2

You could add some properties of an object simply like this :

obj = {a : "1", b : "2"};

myObj = {c: "3", d : "4"};
myObj.a = obj.a;
myObj.b = obj.b;

Update:

In that case just do this :

for(var prop in obj) myObj[prop] = obj[prop];

And to filter out the unwanted properties inside the loop body you could also do this :

for (var prop in obj) {
    if (obj.hasOwnProperty(prop)) {
        myObj[prop] = obj[prop];
    }
}

Answer 3

You can use jQuery's extend function: http://api.jquery.com/jquery.extend/

var object1 = {
  apple: 0,
  banana: { weight: 52, price: 100 },
  cherry: 97
};
var object2 = {
  banana: { price: 200 },
  durian: 100
};

// Merge object2 into object1
$.extend( object1, object2 );

Answer 4

A non-jquery option: you could iterate of the keys of the object to be merged.

var myObject={apple: "a", orange: "o"};
var anothObject = {lemon: "l"};

Object.keys(myObject).forEach(function(key) {
    anothObject[key] = myObject[key];
});

At the end of the loop anothObject is {lemon: "l", apple: "a", orange: "o"}