Problem with my second C++ attempt, and using variables

Hey using this code I always end up with the number 1, why is this.

#include <iostream>

using name开发者_如何学Gospace std;
int y;
int x = (y + 1);

int main()
{
   cin >> y;
   cout << x << endl;
   return 0;
}

The line:

int x = (y + 1);

doesn't auto-magically tie the value of x to be always y + 1. Because you're setting it when y is zero (as a file-level variable, y is be initialised to 0) and never changing it, x will be 1. If you want x to change with y, you should set x whenever y changes, such as with this:

#include <iostream>

int y, x;

int main (void) {
   std::cin >> y;
   x = y + 1;
   std::cout << x << std::endl;
   return 0;
}

because at initialisation y probably is set to 0 and thus x = 0 + 1 = 1; you have to use a function for obtaining your desired behaviour like

int yPlusOne(int y) { return y + 1};
int main() { 
    cin >> y;
    cout << yPlusOne(y) << endl; 
    return 0;
}

This is not how the C++ works at all.

You defined the y variable, then the x variable with some initial value. In the main function, you load new value to y, but x stays unchanged. You need to write what to do with the value in y, so put the line x = y + 1 between the lines with input and output:

#include <iostream>

using namespace std;
int y;
int x;

int main()
{
   cin >> y;
   x = y + 1;
   cout << x << endl;
   return 0;
}