Trailing Closure Syntax

Properties2

Type	Concept
Note created	Feb 17, 2025

Swift provides a shorthand syntax when passing a closure to a function. The syntax is the simpler when the function accepts a single function:

func stuff(f: () -> Void) {
	// ...
}
 
// Regular syntax
stuff(by: { print("Hello!") })
// Trailing shorthand
stuff { print("Hello!") }

The syntax is a bit more complicated when there are multiple functions being accepted:

func complicatedStuff(first: () -> Void, second: () -> Void, third: () -> Void) {
	// ...
}
 
complicatedStuff {
	print("First!")
} second: {
	print("Second!")
} third: {
	print("Third!")
}