Unlock the Power of Set Operations in Swift

The Syntax of subtract()

The subtract() method takes a single parameter, otherSet, which represents the set of elements to be subtracted from the original set. The syntax is straightforward:

set.subtract(otherSet)

Note that otherSet must be a finite set.

How subtract() Works

When you call subtract() on a set, it returns a new set containing only the elements that are present in the original set but not in otherSet. In other words, it removes the common elements between the two sets.

Real-World Examples

Let’s explore two examples to illustrate how subtract() works in practice.

Example 1: Computing Set Differences

Imagine you have two sets, A and B, and you want to find the elements that are unique to A. By using subtract(), you can easily compute the difference between A and B. Similarly, you can find the difference between B and C.

let setA: Set = [1, 2, 3, 4, 5]
let setB: Set = [4, 5, 6, 7, 8]

let difference = setA.subtracting(setB)
print(difference) // Output: [1, 2, 3]

Example 2: Subtracting Ranges

In this example, we create a range of numbers from 1 to 14 and assign it to total. We then subtract the set [2, 5, 6] from total using subtract(). The resulting set contains only the numbers that are not present in the subtracted set.

let total: Set = [Int](1...14)
let subtractSet: Set = [2, 5, 6]

let result = total.subtracting(subtractSet)
print(result) // Output: [1, 3, 4, 7, 8, 9, 10, 11, 12, 13, 14]

By mastering the subtract() method, you can simplify your code and perform complex set operations with ease.