JavaScript Tutorials

JavaScript Array entries()
Syntax & Examples

Array.entries() method

The entries() method of the Array class in JavaScript returns a new array iterator object that contains the key/value pairs for each index in the array.

Syntax of Array.entries()

The syntax of Array.entries() method is:

entries()

This entries() method of Array returns a new array iterator object that contains the key/value pairs for each index in an array.

Return Type

Array.entries() returns value of type Iterator.


✐ Examples

1 Using entries() method to iterate over key/value pairs

In JavaScript, we can use the entries() method to iterate over key/value pairs in an array.

For example,

  1. We define an array variable arr with elements ['apple', 'banana', 'cherry'].
  2. We create an iterator using the entries() method on arr.
  3. We use a for...of loop to iterate over each entry in the iterator.
  4. Inside the loop, we log each entry to the console.

JavaScript Program

const arr = ['apple', 'banana', 'cherry'];
const iterator = arr.entries();
for (const entry of iterator) {
  console.log(entry);
}

Output

[0, 'apple']
[1, 'banana']
[2, 'cherry']

2 Using entries() method with destructuring

We can use destructuring with entries() method to extract key/value pairs from the iterator.

For example,

  1. We define an array variable arr with elements ['apple', 'banana', 'cherry'].
  2. We create an iterator using the entries() method on arr.
  3. We use destructuring to extract key/value pairs from the iterator in a for...of loop.
  4. Inside the loop, we log key and value to the console.

JavaScript Program

const arr = ['apple', 'banana', 'cherry'];
const iterator = arr.entries();
for (const [key, value] of iterator) {
  console.log(`Key: ${key}, Value: ${value}`);
}

Output

Key: 0, Value: apple
Key: 1, Value: banana
Key: 2, Value: cherry

Summary

In this JavaScript tutorial, we learned about entries() method of Array: the syntax and few working examples with output and detailed explanation for each example.