Part 2 - Variables

Part 2 of this C# tutorial series is all about variables.

Overview

Variables are keywords that denote storage space for a program to store various data.  The amount of space that is given depends on the type of the variable.  

The most basic form a variable declaration is shown below:

<data type> <variable list>

If you want to get fancy you can add an additional access modifier.  Access modifiers denote who has access to a variable/function, but we will cover that in detail in another tutorial.

<access modifier> <data type> <variable list>

There are two main types of variables; Value and Reference types.

Value Types

Value type variables can be assigned a value directly.  When you declare these variables, the system allocates the appropriate amount of memory for them.  The table below illustrates many of the value types available in C#.

Reference Types

Reference types do not contain data directly, they simply give a reference, or location, to data.  One may ask why you would want references to variables rather than all variables being value typed.  The reason is that if the data inside a reference variable changes, the reference variable automatically reflects those changes.  This makes more sense as you start to delve into complex data types.

A common example is creating an instance of a class, and then setting that instance to a known instance of the class.  By doing that, you have told the second instance of the class to point to the original.

Example of a reference type: 
string name = "Drew"

Example

Look at the following picture at the right.  Come up with different attributes that you could store as variables for the object.

Examples:
Color of the gear
Number of spokes on the gear
Background Color

Video