How do I use mathematical functions like sqrt(), floor(), round(), sin(), etc?
When doing:
For people using swift [2.2] on Linux i.e. Ubuntu, the import is different!
The correct way to do this is to use Glibc. This is because on OS X and iOS, the basic Unix-like API's are in Darwin but in linux, these are located in Glibc. Importing Foundation won't help you here because it doesn't make the distinction by itself. To do this, you have to explicitly import it yourself:
#if os(macOS) || os(iOS)
import Darwin
#elseif os(Linux) || CYGWIN
import Glibc
#endif
You can follow the development of the Foundation framework here to learn more
As pointed out by @Cœur, starting from swift 3.0 some math functions are now part of the types themselves. For example, Double now has a squareRoot function. Similarly, ceil, floor, round, can all be achieved with Double.rounded(FloatingPointRoundingRule) -> Double.
Furthermore, I just downloaded and installed the latest stable version of swift on Ubuntu 18.04, and it looks like Foundation framework is all you need to import to have access to the math functions now. I tried finding documentation for this, but nothing came up.
➜ swift
Welcome to Swift version 4.2.1 (swift-4.2.1-RELEASE). Type :help for assistance.
1> sqrt(9)
error: repl.swift:1:1: error: use of unresolved identifier 'sqrt'
sqrt(9)
^~~~
1> import Foundation
2> sqrt(9)
$R0: Double = 3
3> floor(9.3)
$R1: Double = 9
4> ceil(9.3)
$R2: Double = 10