C++ LANGUAGE GLOBAL VARIABLES PAGE 21

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C++ LANGUAGE GLOBAL VARIABLES

Global Variables 


Global variables are defined outside of all the functions, usually on 
top of the program. The global variables will hold their value throughout 
the life-time of your program. 
A global variable can be accessed by any function. That is, a global 
variable is available for use throughout your entire program after its 
declaration. Following is the example using global and local variables: 

#include <iostream> 

using namespace std; 

  
// Global variable declaration: 
int g; 
  
int main () 
{ 
  // Local variable declaration: 
  int a, b; 
  
  // actual initialization 
  a = 10; 
  b = 20; 
  g = a + b; 
  
  cout << g; 
  
  return 0; 
} 
A program can have same name for local and global variables but 
value of local variable inside a function will take preference. 
For example: 

#include <iostream> 

using namespace std; 
  
// Global variable declaration: 
int g = 20; 
  
int main () 
{ 
  // Local variable declaration: 
  int g = 10; 
  
  cout << g; 
  
  return 0; 
} 
When the above code is compiled and executed, it produces the following result: 
10