What's your preference on writing functions: ByRef manipulation or returning values?

Hi guys,

I was wondering about this and thought I'd ask this here.

Personally I find that code readability is really important, if not the most important part of software development.

So given the following examples, which one do you think is more readable?

Code:

---

// example 1 (return result)
public function doSomething1(String someString):String{
 /* some manipulation on someString */
 return someString;
}
public function doSomething2(String someString):String{
 /* some manipulation on someString */
 return someString;
}


//example 2 (ByRef)
public function doEverything(String someString1, String someString2):void{
    someString1 = doSomething1(someString1);
    someString2 = doSomething2(someString2);
}

---

Which function would you call if you needed to apply the actions doSomething1 and doSomething2 to strings? Does it make sense to group the actions into a wrapper which manipulates the strings accordingly? Is there a magic number at which you would start wrapping your functions?
Does the Single-Responsability-Pattern still apply assuming that the actions doSomething1 and doSomething2 are strongly related?


Discuss :)

Laurent

I prefer to pass in, out, in/out variables as arguments, and return an error code, which would be 0 if everything went well, or some value if something went wrong.

Code:

---

//example 3 (ByRef in doEverything and also in doSomething, and return code)
public function doEverything(String someString1, String someString2):int
{
  int errorCode = doSomething1(someString1);
  if (errorCode != 0) return(errorCode);

  errorCode = doSomething2(someString2);
  return(errorCode);
}

---

Hi olivthill2,

I like your view on this as it cover both business and error cases. However I think that for error management we should re-use an existing mechanism, such as exceptions? It would probably make the code more read-able and create an alternative stream in your code for error handling.

In your case, for instance, you'd error check by comparing the output, such as:

Code:

---

    int manipulationOutcome = doEverything(someString1, someString2);
    if (manipulationOutcome != 0) {
        System.err.println("something went terribly wrong");
    }

---

In comparison the exception-based one

Code:

---

try{
doEverything(someString1, someString2);
}catch (Exception e){
        System.err.println("something went terribly wrong:" + e.getStackTrace());
}

---

I know that error handling was not the main purpose of this thread but I thought I should still point it out.


What do you think about returning an array of results from a function? I know that it would probably overcomplicate the problem but would it make it more readable?


I always try to avoid ByRef so as to make functions behave as clearly as possible. Sometimes I'd even make a function explicitly return a value eventhough it wouldn't be necessary, like so:

Code:

---

public function doSomething1(String someString):String{
 someString = "." + someString + ".....";
 return someString;
}

---

This doesn't cost anything performance-wise yet makes the code more readable IMO..

Laurent