Operator 'sizeof' with conditional (ternary) expression

Question

I have a hard time understanding sizeof\'s behaviour when given a ternary expression.

#define STRING \"a s         


        

Answer 1

You have to understand expressions, which are the core component of the language.

Every expression has a type. For an expression e, sizeof e is the size of the type of the value of the expression e.

The expression a ? b : c has a type. The type is the common type of the two operand expressions b and c.

In your example, the common type of char[9] and char[1] is char * (both array-valued expressions decay to a pointer to the first element). (In C++, the rules for string literals are different and there is a const everywhere.)