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c++syntax-error

lvalue required as left operand of assignment 2

#include <iostream>
using namespace std;
int main()
{
    int g1, m1, s1, g2, m2, s2, x, y, z;
    cin >> g1 >> m1 >> s1 >> g2 >> m2 >> s2;
    x=g1+g2;
    y=m1+m2;
    z=s1+s2;
    if(m1+m2>59) x+1 && y=y-60;
    if(s1+s2>59) y+1 && z=z-60;
    cout << x << y << z;
}

I'm new to c++ and don't know how to fix it, can someone help me?

Solution

  • The problem is that assignment operator = has the lowest precedence in your expressions:

    if(m1+m2>59) x+1 && y=y-60;
if(s1+s2>59) y+1 && z=z-60;

    Thus, the compiler sees the expressions like this:

    (x + 1 && y) = (y - 60);
(y + 1 && z) = (z - 60);

    And the result of (x + 1 && y) and (y + 1 && z) cannot be assigned, because it's an rvalue.

    Instead you probably want the assignment to take place prior to evaluating result of &&:

    if(m1 + m2 > 59) x + 1 && (y = y - 60);
if(s1 + s2 > 59) y + 1 && (z = z - 60);