A basic question about output of decimals

[Sinusxdx]

It seems very puzzling to me, but this simple code returns 0 and not 0.27. What am I doing wrong?

 #include <iostream>
#include <stdlib.h>

int main()
{
    int c = 27; 
    float p =  0 ;
    p = c/100;
    std::cout << p << std::endl;
}

Addition: Thank everyone for the replies!

[jlb]

Since c and 100 are integers you are doing integer math, meaning there are no fractional parts. To force floating point math at least one of the variables must be a floating point number. In this case you could either cast c to a float or use a float constant 100.0f.

[JayhawkZombie]

You are doing integer division, and integers truncate towards zero. When you divide c by 100, you get 0.27, but because "c" is an integer, the decimals are truncated off and you're left with 0. Change "c" to a float or double and you should get your decimal. You can also divide it by "100.0" instead of 100, and you should get your decimals.

[kevinkjt2000]

This answer on StackOverflow quotes a small portion of the C++ standard about integer division
http://stackoverflow.com/questions/3602827/what-is-the-behavior-of-integer-division-in-c

6.5.5 Multiplicative operators
6. When integers are divided, the result of the / operator is the algebraic quotient with any fractional part discarded.88) If the quotient a/b is representable, the expression (a/b)*b + a%b shall equal a.

In other words integer division simply removes the fractional part (a.k.a.

truncation toward zero

).

So to get around this in your code:
cast either c or 100 before division to a float/double type,
change the type of c to float/double, or
change 100 to 100.0 which is a double constant instead of an integer constant