In this article, we will see how to concatenate N arrays in JavaScript. The efficient way to concatenate N arrays can depend on the number of arrays and the size of arrays.
To concatenate N arrays, we use the following methods:
- Using push() Method
- Using concat() Method
- Using Spread Operator
Method 1: Using push() Method
We create the N arrays and then concatenate the array by using the push() method. In this, we also use the spread operator(…) which iterates over each of the values.
Javascript
const arr1 = [11, 12, 13];const arr2 = [14, 15, 16];arr1.push(...arr2);console.log(arr1); |
[ 11, 12, 13, 14, 15, 16 ]
Method 2: Using concat() Method
First, we will create N arrays and then apply the concat() method to concatenate N arrays. The concat() method is used to merge N arrays together. This method does not alter the original arrays and returns the new Array.
Example:
Javascript
const arr1 = [11, 12, 13],      arr2 = [14, 15, 16],      arr3 = [17, 18, 19],      arr4 = [1, 3, 7];Â
const arr = arr1.concat(arr2, arr3, arr4);Â
console.log(arr); |
[ 11, 12, 13, 14, 15, 16, 17, 18, 19, 1, 3, 7 ]
Method 3: Using Spread Operator
You can also use Spread Operator to concatenate N arrays. For this, first, we will create N arrays and then apply Spread Operator to concatenate N arrays.Â
Note: This method is faster and less memory intensive than the concat() method.
Example:
Javascript
const arr1 = [11, 12, 13],      arr2 = [14, 15, 16],      arr3 = [17, 18, 19],      arr4 = [1, 3, 7];Â
const arr = [...arr1, ...arr2, ...arr3, ...arr4];Â
console.log(arr); |
[ 11, 12, 13, 14, 15, 16, 17, 18, 19, 1, 3, 7 ]
