# Javascript program for union and intersection of two arrays.

```javascript

//Union
function union(arr1, arr2) {
  const arr3 = [ ...new Set([...arr1, ...arr2])]
  return arr3
}
console.log(union(['orange', 'green', 'blue'], ['yellow', 'white', 'blue']))
function union(arr1, arr2) {
  const arr3 = arr1.concat(arr2)
  
  return arr3
}
console.log(union(['orange', 'green', 'blue'], ['yellow', 'white', 'blue']))

//intersection
function performIntersection(arr1, arr2) {
    // converting into Set
    const setA = new Set(arr1);
    const setB = new Set(arr2);

    let intersectionResult = [];

    for (let i of setB) {

        if (setA.has(i)) {
            intersectionResult.push(i);
        }

    }

    return intersectionResult;

}

const array1 = [1, 2, 3, 5, 9];
const array2 = [1, 3, 5, 8];

const result = performIntersection(array1, array2);
console.log(result);
```