Defaults in Function Parameters
Give parameters default values to simplify call sites.
What Are Default Parameters
A function parameter can have a default value. Callers may omit that argument, and Swift fills in the default automatically.
func greet(name: String = "Guest") {
print("Hello, \(name)")
}
greet()
greet(name: "Ada")Declaring a Default
You assign a default after the parameter type using =. The default is used only when the caller does not pass that argument.
func power(base: Int, exponent: Int = 2) -> Int {
var result = 1
for _ in 0..<exponent { result *= base }
return result
}
print(power(base: 5))
print(power(base: 5, exponent: 3))All lessons in this course
- The Nil-Coalescing Operator
- Chaining Default Values
- Defaults in Function Parameters
- Dictionary Default Subscripts