C++, ternary operator and cout

Question

this code doesn\'t work

int main(){
cout << 5 ? (5 ? 0 : 2) : 5;
system(\"pause\");
return 0;
}

this code works

int main(         


        

Answer 1

This is due to operator precedence rules.

<< has higher precedence than ?, so your first expression is parsed as:

(cout << 5) ? (5 ? 0 : 2) : 5;

Brackets are necessary in this case to get the parse you want.

Answer 2

cout << 5 ? (5 ? 0 : 2) : 5;

is parsed as

(cout << 5) ? (5 ? 0 : 2) : 5;