How do I merge two dictionaries in Javascript? [duplicate]

Question

var a = {}; a['fruit'] = "apple";  var b = {}; b['vegetable'] = "carrot";  var food = {}; 

The output variable 'food' must include both key-value pairs.

Answer 1

You could use Object.assign.

var a = { fruit: "apple" },      b = { vegetable: "carrot" },      food = Object.assign({}, a, b);    console.log(food);

For browser without supporting Object.assign, you could iterate the properties and assign the values manually.

var a = { fruit: "apple" },      b = { vegetable: "carrot" },      food = [a, b].reduce(function (r, o) {          Object.keys(o).forEach(function (k) { r[k] = o[k]; });          return r;      }, {});    console.log(food);

Answer 2

Ways to achieve :

1. Using JavaScript Object.assign() method.

var a = {};  a['fruit'] = "apple";    var b = {};  b['vegetable'] = "carrot";    var food = Object.assign({}, a, b);    console.log(food);

2. Using custom function.

var a = {};  a['fruit'] = "apple";    var b = {};  b['vegetable'] = "carrot";    function createObj(obj1, obj2){      var food = {};      for (var i in obj1) {        food[i] = obj1[i];      }      for (var j in obj2) {        food[j] = obj2[j];      }      return food;  };    var res = createObj(a, b);    console.log(res);

3. Using ES6 Spread operator.

let a = {};  a['fruit'] = "apple";    let b = {};  b['vegetable'] = "carrot";    let food = {...a,...b}    console.log(food)