How to combine two elements in array JavaScript?

To combine two elements in an array in JavaScript, you can use the concat() method, which allows you to merge two or more arrays.

Here is an example of how to use the concat() method to combine two arrays in JavaScript.

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

If you want to combine two elements from the same array, you can use a loop or the slice() method to extract the elements, concatenate them, and then replace the original elements with the concatenated result. Here is an example using a loop.

<script>
 let myArr = ["hello", "world", "how", "are", "you"];
 for (var i = 0; i < myArr.length - 1; i++) {
  if(myArr[i] === "hello" && myArr[i+1] === "world") {
    myArr[i] = myArr[i] + " " + myArr[i+1];
    myArr.splice(i+1, 1);
  }
 }
 console.log(myArr); // output : ['hello world', 'how', 'Arre, 'you']
</script>

How to combine two elements in an array in JavaScript #

In JavaScript, there are lots of method to combine two elements in an array in JavaScript.

1. Use the concat() method to concatenate two arrays.

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

   Try it Yourself »
2. Using array spread syntax (...) to concatenate two arrays.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 5, 6];
    let arr3 = [...arr1, ...arr2];
   
    console.log(arr3); // output: [1, 2, 3, 4, 5, 6]
   </script>

   Try it Yourself »
3. Using the push() method to add elements from one array to another.

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

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4. Using the pop() and unshift() methods to add elements to the beginning of an array.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 5, 6];
    while(arr2.length) {
     arr1.unshift(arr2.pop())
    }
   
    console.log(arr1);// output: [4, 5, 6, 1, 2, 3]
   </script>

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5. Using the splice() method to insert elements from one array into another at a specific position.

   <script>
    let arr1 = [1, 2, 3];
    let arr2 = [4, 5, 6];
    arr1.splice(1, 0, ...arr2);
   
    console.log(arr1); // output: [1, 4, 5, 6, 2, 3]
   </script>

   Try it Yourself »