Do these kind of functions have performance problems? I haven't seen a lot of people use "if" in a parameter for a function.

fun getPrice(

productCount : Int,

discount: Int,

limit = if (productCount == 12) 3 else 6

) {

// codes..

}

As you can see, the parameter

limit

is determined by

productCount

. I just wonder it would be a performance problem when runtime or compiler checks this function would often be changed or not. Of course, Kotlin has immutable parameters in a function but the "if" can be a problem??

There's no performance issue. A default parameter expression is evaluated when you call the function, just the same as if you used that expression as an explicit argument. The reason you don't see code like this very often is probably more to do with style and readability. People don't expect to see logic inside a function signature, so I think it's best to keep default parameter values as simple as possible.

If you check the decompiled code it's just an `if`:

public static void getPrice$default(MediaConsumedProcessor var0, int var1, int var2, int var3, int var4, Object var5) {
      if ((var4 & 4) != 0) {
         var3 = var1 == 12 ? 3 : 6;
      }

      var0.getPrice(var1, var2, var3);
   }

Apart from this, it's somehow strange behaviour to have a derived parameter. Since I could pass in a

productCount

of 12 and still set

limit

to 6.

Thank you guys!