Swift Set subtract()

In this tutorial, we will learn about the Swift Set subtract() method with the help of examples.

The subtract() method returns the set difference between two sets.


var A: Set = ["a", "b", "c", "d"]
var B: Set = ["c", "f", "g"]

// equivalent to A-B A.subtract(B)
print("A-B =",A) // Output: A-B = ["d", "b", "a"]

subtract() Syntax

The syntax of the set subtract() method is:


Here, set is an object of the Set class.

subtract() Parameters

The subtract() method takes a single parameter:

  • otherSet - The set of elements.

Note: The other must be a finite set.

subtract() Return Value

  • The subtract() method returns set after removing the common elements of set and otherSet.

Example 1: Swift Set subtract()

var A: Set = [1,2,3,4]
var B: Set = [2,3,6,8]
var C: Set = [5,6,7,8]

// compute A-B A.subtract(B)
print("A-B=", A)
// compute B-C B.subtract(C)
print("B-C=", B)


A-B= [4, 1]
B-C= [3, 2]

Here, we have used the subtract() method to compute the subtraction between A and B & B and C respectively.

Example 2: Use of Swift subtract() and Ranges

// create a set that ranges from 1 to 4
var total = Set(1...4)

// compute subtraction total.subtract([2,5,6])


[3, 1, 4]

Here, 1...14 represents a set of numbers that ranges from 1 to 4 and is assigned to total.

Finally, we have computed the subtraction between total and [2,5,6].

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