Functions with overloads.md

Functions with overloads

There are some peculiarities when using the same parameter names. Functions with the same name and parameter names have their parameters renamed.

Explanations

In Kotlin, we can overload functions with the same name, as long as they have different types in their parameter list.

// FunctionsWithOverloads.kt

fun overloadFunction(param: Int) {  
    println("Utility.overloadFunction(param: Int) | $param")  
}  
  
fun overloadFunction(param: Long) {  
    println("Utility.overloadFunction(param: Long) | $param")  
}  
  
fun overloadFunction(param: Float) {  
    println("Utility.overloadFunction(param: Float) | $param")  
}  
  
fun overloadFunction(param: Double) {  
    println("Utility.overloadFunction(param: Double) | $param")  
}  
  
fun overloadFunction(param: String) {  
    println("Utility.overloadFunction(param: String) | $param")  
}  
  
fun overloadFunction(param: Boolean) {  
    println("Utility.overloadFunction(param: Boolean) | $param")  
}

However, in Swift we can overload functions with the same name, as long as they have different names in their parameter list. Therefore, when this example is compiled to Swift, an underscore is added to the parameter names to distinguish functions from each other. For each subsequent function, another underscore is added.

FunctionsWithOverloadsKt.overloadFunction(param: true)  // Bool
FunctionsWithOverloadsKt.overloadFunction(param_: 2.0)  // Double
FunctionsWithOverloadsKt.overloadFunction(param__: 2.0) // Float
FunctionsWithOverloadsKt.overloadFunction(param___: 2)  // Int32
FunctionsWithOverloadsKt.overloadFunction(param____: 4) // Int64
FunctionsWithOverloadsKt.overloadFunction(param_____: "123")

Accordingly, if you use different parameter names each time, then everything will be fine.

In Kotlin it is:

//FunctionsWithOverloads2.kt

fun anotherOverload(intParam: Int) {
    println("anotherOverloadsWithDifferNames.kt.anotherOverload(param: Int) | $intParam")
}

fun anotherOverload(longParam: Long) {
    println("anotherOverloadsWithDifferNames.anotherOverload(param: Long) | $longParam")
}

fun anotherOverload(floatParam: Float) {
    println("anotherOverloadsWithDifferNames.anotherOverload(param: Float) | $floatParam")
}

In Swift it is:

funс example() {
    FunctionsWithOverloads2Kt.anotherOverload(intParam: 1)
    FunctionsWithOverloads2Kt.anotherOverload(longParam: 1)
    FunctionsWithOverloads2Kt.anotherOverload(floatParam: 1.0)
}

---

Table of contents