---
title: "-(_:_:)"
framework: swift
role: symbol
role_heading: Operator
path: "swift/int128/-(_:_:)"
---

# -(_:_:)

Subtracts one value from another and produces their difference.

## Declaration

```swift
static func - (a: Int128, b: Int128) -> Int128
```

## Discussion

Discussion The subtraction operator (-) calculates the difference of its two arguments. For example: 8 - 3                   // 5 -10 - 5                 // -15 100 - -5                // 105 10.5 - 100.0            // -89.5 You cannot use - with arguments of different types. To subtract values of different types, convert one of the values to the other value’s type. let x: UInt8 = 21 let y: UInt = 1000000 y - UInt(x)             // 999979