How to store multiple arrays in one array in JavaScript

To store multiple arrays in one array in JavaScript, you can simply create an array and push the other arrays as elements of the main array. The example is given below.

<script>
 let arr1 = [1, 2, 3];
 let arr2 = [4, 5, 6];

 let finalArr = [];
 finalArr.push(arr1, arr2);

 console.log(finalArr);
</script>

Try it Yourself »

In this example, we create two arrays arr1 and arr2. Then, we create a main array finalArr and push the other arrays as elements of the main array using the push() method. This creates a nested array structure where each element of the main array is an array itself.

How to store multiple arrays in one array in JavaScript #

1. You can create an empty main array and then use the push() method to add other arrays as elements.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 5, 6];
   
    let finalArr = [];
    finalArr.push(arr1, arr2);
   
    console.log(finalArr); // [[1, 2, 3], [4, 5, 6]]
   </script>

   Try it Yourself »
2. If all of the arrays you want to store in the main array have a similar format, you can create them using a loop and then add them to the main array.

   <script>
    let finalArr = [];
    for (let i = 0; i < 5; i++) {
     let arr = [i, i+1, i+2];
     finalArr.push(arr);
    }
   
    console.log(finalArr);
   </script>

   Try it Yourself »
3. You can use the concat() method to merge two arrays and store the result in a new array.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 5, 6];
   
    let finalArr = arr1.concat(arr2);
   
    console.log(finalArr); // [1, 2, 3, 4, 5, 6]
   </script>

   Try it Yourself »
4. If you have multiple arrays and want to merge them into a single array, you can use the spread operator (...) to expand the arrays into individual elements, and then use the concat() method to merge them all into a single array.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 5, 6];
    let arr3 = [7, 8, 9];
   
    let finalArr = [].concat(...arr1, ...arr2, ...arr3);
   
    console.log(finalArr); // [1, 2, 3, 4, 5, 6, 7, 8, 9]
   </script>

   Try it Yourself »
5. If you need to merge two arrays and remove any duplicates, you can use a combination of the concat() and filter() methods to achieve this.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 2, 1];
   
    let finalArr = arr1.concat(arr2.filter(item => !arr1.includes(item)));
    
    console.log(finalArr); // [1, 2, 3, 4]
   </script>

   Try it Yourself »