scope - Global and local variables in C++ -


i'm new c++, , i'm experiencing issues when printing local , global variables. consider simple piece of code:

#include <cstdlib> #include <iostream>  using namespace std;  /*  *   */ int x = 10; // x global int main() {     int n;     { // pair of braces introduces scope       int m = 10;    // variable m accessible within scope     cout << m << "\n";      int x = 25; // local variable x hides global x     int y = ::x; // y = 10, ::x refers global variable x     cout << "global: " << y << "\n" << "local: " << x << "\n";     {         int z = x; // z = 25; x taken previous scope         int x = 28; // hides local variable x = 25 above         int t = ::x; // t = 10, ::x refers global variable x         cout << "(in scope, before assignment) t = " << t << "\n";         t = x; // t = 38, treated local variableout not declared in scope         cout << "this hidden scope! \n";         cout << "z = " << z << "\n";         cout << "x = " << x << "\n";         cout << "(in scope, after re assignment) t = " << t << "\n";     }      int z = x; // z = 25, has same scope y     cout << "same scope of y. @ code! z = " << z;     }     //i = m; // gives error, since m accessible within scope      int m = 20; // ok, since defines new variable m     cout << m;      return 0; }

my goal practicing accessibility of variables within various scopes, , printing them. however, i'm not able figure out why when try print last variable z, netbeans gives me output 2025. here follows sample output:

10 global: 10 local: 25 (in scope, before assignment) t = 10 hidden scope!  z = 25 x = 28 (in scope, after re assignment) t = 28 same scope of y. @ code! z = 2520 run finished; exit value 0; real time: 0ms; user: 0ms; system: 0ms

hope can me understanding going on! :)

is not z holding value 2520 fact ommit add new line operator between printing z , printing m...

you doing:

cout << "same scope of y. @ code! z = " << z; }  int m = 20;   cout << m;

but should do:

std::cout << "same scope of y. @ code! z = " << z << std::endl; }  int m = 20;   std::cout << m << std::endl;

if followed same criteria of labeling output , doing like

std::cout << "m is: "<<m << std::endl;

you spotted issue faster observing output:

25m is: 20

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