JavaScript Object.fromEntries()

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.

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.

Recommended Reading:

• JavaScript Object.entries()