C++ Beginner : How to Using Local, Global Variables In C++

C++ for beginners : How to Using Local Variables inside a functions or block and Global Variables outside of all the functions In C++? As we know, the c++ programming language also have variables was defined in a of functions or a block or outside of the functions.

Read : C vs C++ programming Languages
If Statements in C++

Today we will learn C++ programming languages just for beginner, where we learn how to using local variables and global variables in a functions or block.

Local Variables

Local variables can be declared inside a function or block. A local variables only can used inside of a functions or a block, the statements that are outside the function cannot use this local variables. Here is the example using local variables :

#include 
using namespace std;

int main (){
  // Declaration Local variable
  int x, y;
  int z;

  // initialization block
  x = 5;
  y = 15;
  z = x + y;

  cout << z;

  return 0;
}

Global Variables

Global variables is declared outside of a block or a functions, the global variables are usually declared in the top line of a program. Not just for programming language C++, but almost the entire programming language has same with the C++ language.

The virtue of global variables is accessible to of anything functions in the programs. because a global variable is created to be accessible from the existing all in a program. Here is the example using Global variables :

#include 
using namespace std;
 
// Declaration Global variable
int x;
 
int main ()
{
  // Declaration Local variable
  int y, z;
 
  // initialization block
  y = 25;
  z = 55;
  x = y + z;
 
  cout << x;
 
  return 0;
}

A Program may have the same variable name for local and global variables, but the value used is the value of a local variable. As an example:

#include 
using namespace std;
 
// Declaration Global variable
int x = 100;
 
int main ()
{
  // Declaration Local variable
  int x = 25;
 
  cout << x;
 
  return 0;
}

When the program is running will result "25"