This article illustrates the various operations that can be applied in a set. There are various operations that can be applied on a set that are listed below:
- Union of sets
- Intersection of sets
- Set difference
- Set Subset Operation
Union of sets
A union set is the combination of two elements. In mathematical terms, the union of two sets is shown by A ∪ B. It means all the elements in set A and set B should occur in a single array. In JavaScript, a union set means adding one set element to the other set.
Example:
Javascript
function showUnion(sA, sB) { const union = new Set(sA); for (const num of sB) { union.add(num); } return union; } const s1 = new Set(['1', '6', '8']); const s2 = new Set(['2', '3', '4']); console.log(showUnion(s1, s2)); |
Set(6) { '1', '6', '8', '2', '3', '4' }
Intersection of sets
An intersection of two sets means the element that occurs in both sets. In mathematical terms, the intersection of two sets is shown by A ∩ B. It means all the elements which is common in set A and set B should occur in a single array.
Example:
Javascript
function getIntersection(set1, set2) { const ans = new Set(); for (let i of set2) { if (set1.has(i)) { ans.add(i); } } return ans; } const set1 = new Set([1, 2, 3, 8, 11]); const set2 = new Set([1, 2, 5, 8]); const result = getIntersection(set1, set2); console.log(result); |
Set(3) { 1, 2, 8 }
Set difference
Set difference means that the array we subtract should contain all the unique element which is not present in the second array.
Example:
Javascript
let A = [7, 2, 6, 4, 5]; let B = [1, 6, 4, 9]; const set1 = new Set(A); const set2 = new Set(B); const difference = new Set(); set1.forEach(element => { if (!set2.has(element)) { difference.add(element); } }); console.log([...difference]); |
[ 7, 2, 5 ]
Set Subset Operation
The set subset operation returns true if all the elements of setB are in setA.
Example:
Javascript
function subSet(val1, val2) { // Get an iterator for val2 const iterator = val2.values(); let nextVal = iterator.next(); while (!nextVal.done) { if (!val1.has(nextVal.value)) { return false; } nextVal = iterator.next(); } return true; } // Two sets const val1 = new Set(['HTML', 'CSS', 'Javascript']); const val2 = new Set(['HTML', 'CSS']); const result = subSet(val1, val2); console.log(result); |
true
