JavaScript Program to Merge Two Arrays and Remove Duplicate Items

Example 1: Using concat() and for Loop

Output

[1, 2, 3, 5]

In the above program, the two array elements are merged together and the duplicate elements are removed.

Here,

• The two arrays are merged using the concat() method.
• The for...of loop is used to loop through all the elements of arr.
• The indexOf() method returns -1 if the element is not in the array.

Hence, during each iteration, if the element equals -1, the element is added to the uniqueArr array using the push() method.

Example 2: Using Spread Syntax and Set

Output

[1, 2, 3, 5]

In the above program, two arrays are merged together and Set is used to remove duplicate items from an array.

The Set is a collection of unique values.

Here,

• Two array elements are merged together using the spread syntax ...
• The array is converted to Set and all the duplicate elements are automatically removed.
• The spread syntax ... is then used to include all the elements of the set back to an array.