C++ Variables

Variables in C++ are used store a value. C++ allows the declaration of a variable anywhere in the scope. It means that a variable can be declared right at the place of its first use. There are some rules in C++ for choosing a variable name as same a C. They are following:

• Must begin with a letter or underscore.
• First 31 characters are significant.
• Variables name are case sensitive.
• consist of Capital letters(A-Z), lowercase letters(a-z), digits(0-9), and the underscore character.
• Should not be a keyword.
• White space is not allowed.
• Special characters are not allowed.

There are the following variable types in C++:

Example of a c++ program using variable is given below:

#include <iostream>
using namespace std;
int main()
{
    int first_number, second_number, sum;
    
    cout << "Enter two integers: ";
    // Two integers entered by user stored
    cin >> first_number >> second_number;
    // Sum of the two numbers stored in the variable sum
    sum = first_number + second_number;
    // Displaying the value of sum      
    cout <<  first_number << "+" <<  second_number <<  "="  <<  sum;
    return 0;
}

Enter two integers: 7
17
7 + 17 = 24