Operator

-(_:_:)

Subtracts one value from another and produces their difference.

Required.

Declaration

override static func - (lhs: Self, rhs: Self) -> Self

Parameters

lhs

A numeric value.

rhs

The value to subtract from lhs.

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