JavaScript merge arrays without duplicates | Example code

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There are multiple ways to merge arrays without duplicates in JavaScript. Commonly used methods are concat() with for Loop, Spread Syntax with Set, Set, etc.

Example merge arrays without duplicates in JavaScript

Simple example code using concat() and for Loop. The indexOf() method returns -1 if the element is not in the array.

<!DOCTYPE html>
<html>
<head>

  <script>

    const arr1 = [1, 2, 3];
    const arr2 = [2, 3, 5];

    // merge two arrays
    let arr = arr1.concat(arr2);
    let uniqueArr = [];

    // loop through array
    for(let i of arr) {
      if(uniqueArr.indexOf(i) === -1) {
        uniqueArr.push(i);
      }
    }
    
    console.log(uniqueArr);
  </script>

</head>
</html>

Output:

JavaScript merge arrays without duplicates

Using Spread Syntax and Set

The array is converted to Set and all the duplicate elements are automatically removed.

<script>

    const arr1 = [1, 2, 3];
    const arr2 = [2, 3, 5];
    
    // merge two arrays
    let arr = [...arr1, ...arr2];

    // removing duplicate
    let uniqueArr = [...new Set(arr)];

    console.log(uniqueArr);
</script>

Do comment if you have any doubts or suggestions on this JS merging array topic.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.

OS: Windows 10

Code: HTML 5 Version

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