Get first element of array in JavaScript

This post will discuss how to get the first element of an array in JavaScript.

1. Using `[]` operator

A simple and fairly efficient solution to fetch the first element of an array in JavaScript is using the [] operator. This method is demonstrated below:

var arr = [ 1, 2, 3, 4, 5 ];

var first = arr[0];

console.log(first);

Output: 1

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2. Using `Array.prototype.shift()` function

The shift() method returns the first element from an array but removes it from the array as well. To avoid modifying the original array, you can create a copy of the array before calling the shift() method. You can do this in two ways:

⮚ Slicing

var arr = [ 1, 2, 3, 4, 5 ];

var first = arr.slice(0, 1).shift();

console.log(first);

Output: 1

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⮚ ES6 Spread operator

var arr = [ 1, 2, 3, 4, 5 ];

var first = [...arr].shift(); // costly for large arrays

console.log(first);

Output: 1

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3. Using Destructuring Assignment

Alternatively, you can use the Destructuring Assignment syntax to get the first element of the array.

var arr = [ 1, 2, 3, 4, 5 ];

const [first] = arr;

console.log(first);

Output: 1

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4. Using jQuery

With jQuery, you can pass index 0 to .get(index) to retrieve the first element.

const { JSDOM } = require("jsdom");

const { window } = new JSDOM();

var $ = require("jquery")(window);

var arr = [ 1, 2, 3, 4, 5 ];

var first = $(arr).get(0);

console.log(first);

Output: 1

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5. Using Underscore/Lodash Library

Alternatively, with the Underscore JavaScript library, you can use the _.first method, which simply returns the first element of an array if no arguments are specified. Its aliases _.head and _.take can also be used.

var _ = require('underscore');

var arr = [ 1, 2, 3, 4, 5 ];

var first = _.first(arr);

console.log(first);

Output: 1

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Similarly, Lodash has the _.head method, which returns the first element of an array. Its alias _.first can also be used.

var _ = require('lodash');

var arr = [ 1, 2, 3, 4, 5 ];

var first = _.head(arr);

console.log(first);

Output: 1

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That’s all about getting the first element of the array in JavaScript.

Get first element of array in JavaScript

1. Using [] operator

2. Using Array.prototype.shift() function

⮚ Slicing

⮚ ES6 Spread operator

3. Using Destructuring Assignment

4. Using jQuery

5. Using Underscore/Lodash Library

Share this:

1. Using `[]` operator

2. Using `Array.prototype.shift()` function