: Hi,
:
: I accidentally wrote this:
:
: if (1, 2);
Except when given a different meaning by context (for
instance to separate function parameters, or initializers),
a "," in C and C++ is interpreted as a comma operator:
This operator first evaluates the left hand side expression,
then evaluates the right hand side expression. The result
is the right hand side expression.
if( 1, 2 ) -> condition will always pass (value is 2 -> true)
if( 0, 1 ) -> condition will always pass (value is 1)
if( 0, 0 ) -> condition will always fail (value is 0)
To experiment with this, you may write:
cout << ( 1, 2 ); // prints 2
cout << ( 99, "HELLO" ); // prints HELLO
cout << ( 1, 4, "TEST", 3 ); // prints 3
etc
: and it compiles fine. I want to know why is it correct and what does
: it mean in c++. The compiler i'm using in visual C++ 2k5.
The behavior you observed was correct.
Hope this helps -Ivan
