Question

I have some code that’s written like so:

private double function1()
{
    double result2 = function2();
    if (result2  < 0) { return result2; }

    double result3 = function3();
    if (result3  < 0) { return result3; }

    return 0;
}

I need to re-write it such that it has only one return statement. Is there an easy way to do this? It strikes me as inefficient to begin with that the same if construct is used twice. How can this inefficiency be cleaned up?

Answer 1

Keep it simple, keep it readable.

// direct conversion of your code
private double function1()
{
    double result = 0;

    double result2 = function2();
    if (result2  < 0) 
    {
      result =  result2; 
    }
    else
    {
       double result3 = function3();
       if (result3  < 0) 
       {
         result = result3; 
       }
    }

    return result;
}

---

A shorter version, probably easier on the eyes:

private double function1()
{
    double result = function2();

    if (result >= 0)   // if (!(result < 0))  to be safe for NaN
    {
       result = function3();
       if (result >= 0) 
       {
         result = 0; 
       }
    }    
    return result;
}

---

And

It strikes me as inefficient to begin with that the same if construct is used twice.

There is nothing inefficient about that. If the pattern was repeated (much) more you could start to think about an extra method or something to aid readability.