JavaScript - merge two objects properties dynamically

In this article, we would like to show you how to merge two object properties dynamically in JavaScript.

Quick solution:

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const result = {

  ...object1,

  ...object2

}

Hint: be careful, presented solutions in this example merged object only on the first level (object1 and object2 direct properties will be combined - without child object properties).

To make full merge it is necessary to iterete grought all objects, or use some library.

In this example, we merge object1 and object2 into the result object.

Spread operator (...) was introduced in ES6.

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const object1 = {

  1: 'a',

  2: 'b'

}

const object2 = {

  2: 'c',

  3: 'd'

}

​

const result = {

  ...object1,

  ...object2

}

​

console.log(JSON.stringify(result, null, 2));

Output:

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{

  "1": "a",

  "2": "c",

  "3": "d"

}

Note:

If the property from object2 is the same as property from object1, it will be overwritten.

Object.assign() was introduced in ES6.

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const object1 = {

  1: 'a',

  2: 'b'

}

const object2 = {

  2: 'c',

  3: 'd'

}

​

const result = Object.assign({}, object1, object2);

​

console.log(JSON.stringify(result, null, 2));

Note:

If the property from object2 is the same as property from object1, it will be overwritten.