Integer ops, associativity and precedence...

[gwowen]

Is the following function well defined?

int f(int a, int b int c){
return a * b / c;
}

If so, what is f(5,1,3) ?

 

[gwowen]

5 * 1 / 3 is equivalent to (5 * 1) / 3, which is equal to 5/3 = 1,
because multiplication and division (which have the same precedence)
associate left-to-right.

Thank you. Every compiler I used said that, but I couldn't find the
"associate left-to-right" bit in t'standard.

 

[Eric Sosman]

Is the following function well defined?

int f(int a, int b int c){
return a * b / c;
}

No, it's a syntax error.

If so, what is f(5,1,3) ?

A function call. To a function for which no valid
definition has been exhibited.

 

[robertwessel2]

In


In general, yes, but not if overflow occurs (undefined) or c is 0
(undefined) or if either operand is negative
(implementation-defined).

Since I'm in a nit-picky mood...

The last is true only in C89/90, and only if the result is not exactly
an integer. C99 specifies the behavior.