How to use a for loop In Javascript

We can also use a for loop to iterate through the array and extract the first N elements.

Syntax:

for (let i = 0; i < n; i++) {
    // Access and store elements here
}

Example 1: In this example, we have initialized an empty array result and used a for loop to iterate through the first n elements of the original array arr. We accessed and stored the elements in the result array.

Javascript
const arr = [1, 2, 3, 4, 5, 6];
const n = 3; // Number of elements to extract
const result = [];
for (let i = 0; i < n; i++) {
    result.push(arr[i]);
}
console.log(result); // Output: [1, 2, 3]

Output
[ 1, 2, 3 ]


Example 2: In this example, we declare an empty array result to store the extracted elements. Then, we use a for loop to iterate over the elements of the original array arr and push the first n elements to the result array using the push() method. The loop condition is set to terminate when either n elements have been extracted or all the elements of the original array have been processed.

Javascript
const arr = ['apple', 'banana', 'orange', 'grape', 'kiwi'];
const n = 3;

const result = [];

for (let i = 0; i < n && i < arr.length; i++) {
      result.push(arr[i]);
}

console.log(result); // Output: ['apple', 'banana', 'orange']

Output
[ 'apple', 'banana', 'orange' ]


How to Get First N Elements from an Array in JavaScript ?

To get the first N elements from an array is a common task in JavaScript. Whether you’re dealing with lists of data, subsets of results, or pagination, this guide will provide you with several efficient methods to achieve this.

Below are the approaches to get the first N number of elements from an array in JavaScript.

Table of Content

  • 1. Using the slice() method
  • 2. Using a for loop
  • 3. Using the splice() method
  • 4. Using the filter() method
  • 5. Using Lodash _.take() Method
  • 6. Using the spread operator

Examples:

Input:
arr = [1, 2, 3, 4, 5, 6], n = 3 
Output: [1, 2, 3] 

Input:
arr = [6, 1, 4, 9, 3, 5, 7], n = 4
Output: [6, 1, 4, 9]

Similar Reads

1. Using the slice() method

The slice() method is used to extract a part of an array and returns a new array containing the extracted elements. It does not change the original array. Here, start is the starting index from where to begin extraction and end is the ending index from where to end extraction. The end index is exclusive, i.e., the element at the end index is not included in the extracted array....

2. Using a for loop

We can also use a for loop to iterate through the array and extract the first N elements....

3. Using the splice() method

The splice() method can be used to add or remove elements from an array. We can use it to remove all elements after the first N elements. Here, start is the starting index from where to begin deletion, and deleteCount is the number of elements to be deleted. We can set deleteCount to the length of the array to remove all elements after the first N elements....

4. Using the filter() method

We can also use the filter() method but this method is not much efficient because it iterates over the entire array....

5. Using Lodash _.take() Method

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6. Using the spread operator

Another approach to get the first N number of elements from an array in JavaScript is by using the spread operator along with array destructuring. This method creates a shallow copy of the original array with the specified number of elements....

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