C++ Tutorial - Local Variable Vs Global Variable

In this C++ Tutorial we are going to talk about Local Variable Vs Global Variable in C++,

so you can use C++ Variables inside a function in different ways. you can use Variables as

arguments when you are going to call a function. also variables can be shared by the function

and rest of a program. you can create variables in a function locally and globally.

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Local Variables

When you create a variable inside a function it is called local variable. because it exists

only locally within the function itself. When the function returns, all of its local variables

are no longer available for use in the program. you can create local variables like normal

variable creation.

So now let’s create our local variable example.

#include<iostream>

using namespace std;



int main() {

	int a = 7;
	int b = 8;

	int sum = a + b;

	cout << sum << '\n';




	return 0;
}

#include<iostream>

using namespace std;

int main() {

int a = 7;

int b = 8;

int sum = a + b;

cout << sum << '\n';

return 0;

}

You can see in the above example i have created three local variables inside my main() function.

This is the output:

15
Press any key to continue . . .

1 2	15 Press any key to continue . . .

Global Variable

You can create a variable outside of the function in C++, when you create a variable

outside of a function that is called Global Variable, because they are available everywhere

in the program.

Now let’s take a look at this example

#include<iostream>

using namespace std;


//Global variables
int a;
int b;

int sum;


int main() {

    // getting the number from the user input
	cout << "Please enter first number " << '\n';
	cin >> a;

	cout << "Please enter second number : " << '\n';
	cin >> b;

	//adding the numbers
	sum = a + b;


	//printing the outpu
	cout << "Sum is : " << sum << '\n';





	return 0;
}

#include<iostream>

using namespace std;

//Global variables

int a;

int b;

int sum;

int main() {

// getting the number from the user input

cout << "Please enter first number " << '\n';

cin >> a;

cout << "Please enter second number : " << '\n';

cin >> b;

//adding the numbers

sum = a + b;

//printing the outpu

cout << "Sum is : " << sum << '\n';

return 0;

}

So you can see that we have created three variables outside of our main() function,

you can access to this variables in every where of the program.

In this program we are going to just asks two numbers from the user and after that

we are adding these two numbers and print the output in the terminal.

Execute the code this will be the result for C++ Tutorial – Local Variable Vs Global Variable.

Please enter first number
6
Please enter second number :
4
Sum is : 10
Press any key to continue . . .

Please enter first number

Please enter second number :

Sum is : 10

Press any key to continue . . .

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