Question

The C Operator Preference Table notes the higher precedence of ().

Code:

# include <stdio.h>
int main()
{
    int temp=2;
    (temp += 23)++;    //Statement 1
    ++(temp += 23);    //Statement 2
    printf("%d",temp);
    return 0;
}

My question is while parentheses has higher precedence than pre-fix operator in Statement 2 why there’s an error.
In Statement 1 both has same precedence but order of evaluation is from left to right. Still the same error.
Third doubt: operator += has much lower precedence, then why it’s causing error.

error: lvalue required as increment operand

Answer 1

An lvalue is a value that some other value can be assigned to (because it is on the left side of the assignment operator). (temp += 23) is a rvalue. Nothing can be assigned to it.