 # 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.

### Example

``````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:

``set.subtract(otherSet)``

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)``````

Output

```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])

print(total)``````

Output

`[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]`.