How to perform intersection of two sets in JavaScript ?
An intersection of two sets means the element which 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. In javascript, the intersection of two sets means getting the common from both sets.
We can find the intersection of two sets in many ways:
- JavaScript Sets: Set can store any type of value whether primitive or objects.
- JavaScript filter() Method: Create a new array from a given array consisting of only those elements from the given array which satisfy a condition set by the argument method.
- JavaScript set.has() Method: Check whether an element with a specified value exists in a Set or not.
Using Sets & has() Method: A set is a collection of items that are unique i.e no element can be repeated. Set in ES6 are ordered: elements of the set can be iterated in the insertion order. A set can store any type of value whether primitive or objects.
Example 1: In this example, we will see the intersection of sets by using the set.has() method.
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); |
Output:
Set(3) { 1, 2, 8 }
Using the has() & filter() Method: We check if the element is present in set1 also then we are going to add that element to the new set.
Example 2: In this example, we will see the intersection of sets by using the filter() method. We have also used the spread operator for separating the element.
Javascript
let set1 = new Set([1, 2, 3]); let set2 = new Set([4, 3, 2]); let set = new Set([...set1].filter(x => set2.has(x))); console.log(set); |
Output:
Set(2) { 2, 3 }
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