Ok, so you now make out how to inform the compiler regarding variables, but what on using them?

Here is a example program demonstrating the utilize of a variable:

Code:
#include <iostream>

using namespace std;

int main()
{
  int thisisanumber;

  cout<<"Please enter a number: ";
  cin>> thisisanumber;
Code:
cin.ignore();
  cout<<"You entered: "<< thisisanumber <<"\n";
  cin.get();
}
Let's break separately this program as well as check it line by line. The keyword int declares this is a numeral to be an integer. The function cin>> reads a value into this is a number; the client must press enter earlier than the number is examined by the program. cin.ignore() is one more task that reads as well as discards a character. Keep in mind that when you type input into a program, it takes the enter key as well. We don't require this, so we throw it away. Keep in mind that the variable was stated an integer; if the client tries to type in a decimal figure, it will be condensed (that is, the decimal component of the number will be unobserved). Try typing in a series of characters or else a decimal number when you run the case program; the reply will differ from input to input, but in no case is it mainly attractive. Notice that when printing out a variable quotation marks are not used. Were there quotation marks, the output would be "You Entered: thisisanumber." The need of quotation marks notifies the compiler that there is a variable, plus so that the program should confirm the value of the variable in order to restore the variable given name with the variable when accomplishing the output task. Do not be puzzled by the addition of two separate insertion operators on one line. With numerous insertion operators on one line is completely acceptable as well as all of the output will go to the similar place. Actually, you must separate string literals (strings enclosed in quotation marks) along with variables by giving all its own insertion operators (<<). Trying to set two variables jointly with only one << will give you an error message, do not try it. Do not overlook to end functions as well as declarations with a semicolon. If you forget the semicolon, the compiler will present you an error note when you try to compile the program.