When to use 'if…else if' and when to use

Question

1) I know how if…else if statements work, but in the next example both methods are identical as far as the resulting value is concerned. So does it matter which of the two methods I use or should I always go for one that is semantically closest to what the code is trying to do ( here I’m guessing that semantically the two methods are quite different )? So which method would you use and why?

protected string GetNumberDescription(int value)
{
    if (value >= veryBigNumber)
        return veryBigNumberDescription;
    else if (value >= bigNumber)
        return bigNumberDescription;
    else if (value >= smallNumber)
        return smallNumberDescription;
    else
        return "";
}

protected string GetNumberDescription(int value)
{
    if (value >= veryBigNumber)
        return veryBigNumberDescription;
    if (value >= bigNumber)
        return bigNumberDescription;
    if (value >= smallNumber)
        return smallNumberDescription;
    else
        return "";
}

2) I noticed losts of code uses the following format when writting if ... else if statements:

if ...
else if ...
else ...

But isn't ( at least conceptually ) more correct way:

if ...
else
  if ...
  else ...

Answer 1

1. You should probably use the first. It's more accepted, and more logical. (You don't care about anything afterwards if this condition is true... indicate that in your code.)
2. It's generally more accepted, and more compact and readable, to use the first way (else if). Python even has a specific keyword for it (elif).

Answer 2

I personally would use

protected string GetNumberDescription(int value)
   {
       if (value >= veryBigNumber)
           return veryBigNumberDescription;
       if (value >= bigNumber)
           return bigNumberDescription;
       if (value >= smallNumber)
           return smallNumberDescription;
       return string.Empty;
   }

It really all depends on what your function is doing. If its simple like this then keep it simple. If you might need to do something with the result before you return it then I'd use Egrunin's solution