CODEWITHSUNDEEP
swiftfunctionmethodsdeclaration
Rainer Niemann
Rainer Niemann

Reputation: 644

Is there a way to use functions with same names but different return types?

My intention is the following:

My first function:

public mutating func replaceSubstringInRange(_ range: CountableClosedRange<Int>, withString string: String) -> String

that I can use it in a context of print() for example.

And my second:

public mutating func replaceSubstringInRange(_ range: CountableClosedRange<Int>, withString string: String) -> Void

just for modifying something.

I know that there is a different function signature needed, but is there any better way?

Upvotes: 6

Views: 2239

Answers (2)

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 726539

You cannot define two functions with identical parameter types without creating an ambiguity, but you can call a function returning a value as if it were Void. This generates a warning, which you can silence by designating your function result discardable:

@discardableResult
public mutating func replaceSubstringInRange(_ range: CountableClosedRange<Int>, withString string: String) -> String {
}

Upvotes: 3

JTeam
JTeam

Reputation: 1505

You can have two functions with same name, same parameters and different return type. But if you call that function and do not provide any clue to compiler which function of the two to call, then it gives ambiguity error,

Examples:

func a() -> String {
    return "a"
}

func a() -> Void {
    print("test")
}


var s: String;
s = a()
// here the output of a is getting fetched to a variable of type string,
// and hence compiler understands you want to call a() which returns string

var d: Void = a() // this will call a which returns void

a() // this will give error Ambiguous use of 'a()'

Upvotes: 14

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