Unique intersection of arrays in JavaScript

We are required to write a JavaScript function that takes in two arrays of numbers, let’s say arr1 and arr2. The function should find the intersection between the elements of the array. i.e., the elements that appear in both the arrays.

The only condition is that if we encountered one element before as intersected, we should not consider it again even if appears again in both the arrays.

For example −

If the input arrays are −

const arr1 = [1, 5, 7, 3, 1];
const arr2 = [1, 7, 3, 1, 6];

Then the output array should be −

const output = [1, 3, 7];

However, the order is not that important, what’s more, important is not to consider repetitive intersection.

Example

Following is the code −

const arr1 = [1, 5, 7, 3, 1];
const arr2 = [1, 7, 3, 1, 6];
const uniqueIntersection = (arr1, arr2) => {
   const map = new Set();
   const res = [];
   arr1.forEach(el => map.add(el));
   arr2.forEach(el => {
      if (map.has(el)) {
         res.push(el);
         map.delete(el);
      };
   });
   return res;
};
console.log(uniqueIntersection(arr1, arr2));

Output

Following is the output on console −

[1, 7, 3]

AmitDiwan

Published on 10-Dec-2020 08:15:25

• Related Questions & Answers
• Intersection of two arrays JavaScript
• Finding intersection of multiple arrays - JavaScript
• Intersection of three sorted arrays in JavaScript
• Finding intersection of arrays of intervals in JavaScript
• Finding the intersection of arrays of strings - JavaScript
• Intersection of two arrays in C#
• Intersection of two arrays in Java
• Intersection of Two Arrays in C++
• Finding intersection of arrays that contain repetitive entries in JavaScript
• Intersection of Two Arrays II in Python
• Intersection of Three Sorted Arrays in C++
• Merging two arrays in a unique way in JavaScript
• Combine unique items of an array of arrays while summing values - JavaScript
• How to find the intersection of two arrays in java?
• How to get the intersection of two arrays in MongoDB?