Variable is the place to store the piece of information. As one might store the friend's phone number in own memory, we can store this information in the computer's memory. These are the means of accessing the computer's memory.

There are fairly strict rules on how the variables are named which C++ imposes:

• Variable names should start with the letter.
• The variable names are case-sensitive (i.e., variable "myNumber" is different from "MYNUMBER" which inturn is different from "mYnUmBeR").
• Variable names cannot have blank spaces in between.
• A variable names cannot have the special characters.

Variables are of three basic types which are as follows:

1. int
2. float
3. char

Variable type is nothing but a description of the kind of the information a variable will store. Declaring the variable in C++ is simple. Let us say that we want to declare the variable of type int called "myAge". That is to say, Variable myAge will store the integer, Variable myName will store an character, Variable myHeight will store float value. In C++, this is written as shown below:

In C++ Casting is easy. Let us say that we have used a float variable storing the number like "26.3141885", and we want to have the int storing an integer portion instead of the float. This is done as shown below:

The key part to notice here is the line of code which reads int truncatedAvg = (int) totalAvg. What we are doing here is taking the float, totalAverage, that stores some kind of the decimal number (say 82.41832), and getting rid of ".41832" part by casting it to the int. This works since int is the only capable of storing the integers, so it simply stores an integer portion of the totalAvg.