JavaScript Object.fromEntries()

The Object.fromEntries() method creates an object from a list of key-value pairs.

Example

const arr = [
  ["0", "a"],
  ["1", "b"],
  ["2", "c"],
];

// convert the above array into an object const newObj = Object.fromEntries(arr);
console.log(newObj); // Output: { '0': 'a', '1': 'b', '2': 'c' }

fromEntries() Syntax

The syntax of the fromEntries() method is:

Object.fromEntries(iterable)

Here, fromEntries() is a static method. Hence, we need to access the method using the class name, Object.


fromEntries() Parameters

The fromEntries() method takes in:

  • iterable - an iterable such as an Array or a Map or any other object implementing the iterable protocol.

fromEntries() Return Value

The fromEntries() method returns:

  • a new object whose properties are given by the entries of the iterable.

Note: Object.fromEntries() performs the reverse function of Object.entries().


Example: JavaScript Object.fromEntries()

const entries = [  ["firstName", "John"],
  ["lastName", "Doe"]
];

// convert the above array into an object const obj = Object.fromEntries(entries);
console.log(obj); const arr = [ ["0", "x"], ["1", "y"], ["2", "z"], ];
// convert the above array into object const newObj = Object.fromEntries(arr);
console.log(newObj);

Output

{ firstName: 'John', lastName: 'Doe' }
{ '0': 'x', '1': 'y', '2': 'z' }

In the above example, we have first created the entries array, which consists of two key-value pairs: ["firstName", "John"] and ["lastName", "Doe"].

We then used the Object.fromEntries() method to convert the entries array into an object possessing the key-value pairs specified in the array.

const obj = Object.fromEntries(entries); 

The output indicates that the arrays have been converted to their respective objects.

Then, we repeated the same process with the arr array.


Also Read:

Did you find this article helpful?

Your builder path starts here. Builders don't just know how to code, they create solutions that matter.

Escape tutorial hell and ship real projects.

Try Programiz PRO
  • Real-World Projects
  • On-Demand Learning
  • AI Mentor
  • Builder Community