THE MANY FORMS OF SWIFT FUNCTIONS – A CHEATSHEET

swiftFunctionsForms

THE MANY FORMS OF SWIFT FUNCTIONS – A CHEATSHEET
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No parameters, no return value

	func foo()

	called with

	foo()

No parameters, return type

	func foo() -> Int

	called with

	var a = foo()

Single parameter, no return value

	func foo(bar: Int)

	called with

	foo(10)

Single parameter, return value

	func foo(bar: Int) -> Int

	called with

	var a = foo(10)

Multiple parameters, return value

	func foo(bar: int, bash: String) -> Int

	called with

	var a = foo(10, "hello")

One or more parameters, multiple return values

	func foo(bar: Int) -> (bash: Int, baz: String)

	called with

	var a = foo(10, "Hello")

	a.bash = ...
	a.baz = "..."

One or more parameters, optional multiple return values

	func foo(bar: Int) -> (bash: Int, baz: String)?

	called with

	if let a = foo(10) {
	    println ("Bash is \(bash) and baz is \(baz)")
	}

Default parameters

	func foo(bar: Int, bash: String = "bash!") -> Int

	called with

	var a = foo(10)
	var b = foo(10, "bling!")

External parameter names

	func foo(externalBar bar: Int) -> Int

	called with

	var a = foo(externalBar: 10)
	
Opting out of external parameter names with default parameters

        func foo(_ bar: Int, _ bash: String = "bash!") -> Int

        called with

        var a = foo(10)
        var b = foo(10, "Bling!")

Shorthand external parameter names

	func foo(#bar: Int, #bash: String) -> Int

	called with

	var a = foo(bar: 10, bash: "Bling!")

External parameter names with default parameters

	func foo(#bar: Int, bash: String = "bash!") -> Int

	called with

	var a = foo(bar: 10)
	var b = foo(bar: 10, bash: "Bling!")

Variadic parameters

	func foo(bar: Int, bash: String...) -> Int

	called with

	var a = foo(10, "Bling!", "Clang!")

Variable parameters

	func foo(var bar: Int, var bash: String) -> Int

	called with

	var a = foo(10, "Bling!")

In-out parameters

	func foo(inout bar: Int, inout bash: String)

	called with

	var x = 10
	var y = "Bling!"
	foo(&x, &y)

I'm pretty new to Swift, but I think for var b on line 72 you might have meant foo(10, "bash!")

func foo(bar: Int, bash: String = "bash!") -> Int

called with

var a = foo(10)
var b = foo(10, "bling!")