This may be a stupid question, but I just want to somebody can give a better explanation.
I have a method defined as below:
private int Test(int i)
{
if (i < 0) return -1;
if (i == 0) return 0;
if (i > 0) return 1;
//return 0;
}
It gives me this error "not all code path return a value".
I thought I had 3 if statement, which could cover all the scenarios(i<0, i==0, i>0). So it should not show me this error.
The compiler just ain't that clever. Also, you're code is slightly inefficient in that it tests for a certainty (i must be greater than zero in the last case).
Write it as:
private int Test(int i)
{
if (i < 0) return -1;
else if (i == 0) return 0;
else return 1;
}
During compile-time, the compiler doesn't analyze the conditions and understands that they cover all the options - it just sees three unrelated if statements, and a path with no return if none of them are triggered.
You can make it "understand" by using else if and elses:
private int Test(int i)
{
if (i < 0) return -1;
else if (i == 0) return 0;
else return 1;
}
If you want to keep your format, a way to do it is like this...
private int Test(int i)
{
bool result = 1;
if (i < 0) result = -1;
if (i == 0) result = 0;
if (i > 1) result = 1; //This is redundant because i is initialized to 1
return result;
}
Math.Sign(i).int iall scenarios are covered; as an excuse of the false alert, please, note that fordouble ithe warning is correct (double.NaNwill pass all threeifs)double.NaN.