Integer division always zero [duplicate]
Possible Duplicate:
C programming division
probably my question is very simple and stupid.
I would like to store the value of a division, in particular 1 / x
where x
is a
integer value.
int x = 17;
double result = 1/x;
I try to do it but I always get 0.000000 ...
I try to enter a value fixed in x, for example 1/17
but always get the same value .. what's Wrong?
You are doing integer division.
Try the following and it will work as expected:
int x = 17;
double result = 1.0 / x;
The type of the 1
in the expression you have above is int
, and the type of x
is int. When you do int / int
, you get an int back. You need at least one of the types involved to be floating point (float
or double
) in order for floating point division to occur.
Unlike in Mathematics, division in C++ can either refer to truncated integer division (what you did) or floating point division (what I did in my example). Be careful of this!
In my example, explicitly what we have is double / int -> double
.