JS Practice — Built-in Objects

Set isSubsetOf() — empty set is subset of everything

📖 Usage Example

const a = new Set([1, 2])
const b = new Set([1, 2, 3])
a.isSubsetOf(b)   // → true
b.isSubsetOf(a)   // → false

Use Set.isSubsetOf() to check whether every element of this set is also in another set.

Set.prototype.isSubsetOf() (ES2025)

The empty Set is a subset of every Set.

Challenge: Verify that the empty Set is a subset of any Set.

💡 Hints (1)

• The empty Set has no elements that could be missing from B, so it is always a subset