*(_:_:)

The multiplication operator (*) calculates the product of its two arguments. For example:

2 * 3                   // 6
100 * 21                // 2100
-10 * 15                // -150
3.5 * 2.25              // 7.875

You cannot use * with arguments of different types. To multiply values of different types, convert one of the values to the other value’s type.

let x: Int8 = 21
let y: Int = 1000000
Int(x) * y              // 21000000