C++ Tutorial/Function/function scope variables

A local variable is initialized each time its block is entered

<source lang="cpp">#include <iostream> using namespace std;

void f();

int main() {

 for(int i=0; i < 3; i++) f(); 
  
 return 0; 

}

// num is initialized each time f() is called. void f() {

 int num = 99; 

 cout << num << "\n"; 

 num++; // this has no lasting effect 

}</source>

99
99
99

Function level variable

<source lang="cpp">#include <iostream> using namespace std;

void f1();

int main() {

 int val = 10; 

 cout << "val in main(): " << val << "\n"; 
 f1(); 
 cout << "val in main(): " << val << "\n"; 

 return 0; 

}

void f1() {

 int val = 88; 

 cout << "val in f1(): " << val << "\n"; 

}</source>

val in main(): 10
val in f1(): 88
val in main(): 10