Beginning Microsoft® Visual C#® 2008

Chapter 5. More About Variables

Now that you've seen a bit more of the C# language, it's time to go back and tackle some of the more involved topics concerning variables.

The first subject you look at in this chapter is type conversion, whereby you convert values from one type into another. You've already seen a bit of this, but you look at it formally here. A grasp of this topic gives you both a greater understanding of what happens when you mix types in expressions (intentionally or unintentionally) as well as tighter control over the way that data is manipulated. This helps you to streamline your code and avoid nasty surprises.

Then you'll look at a few more types of variables that you can use:

• Enumerations: Variable types that have a user-defined discrete set of possible values that can be used in a human-readable way.

• Structs: Composite variable types made up of a user-defined set of other variable types.

• Arrays: Types that hold multiple variables of one type, allowing index access to the individual value.

These are slightly more complex than the simple types you've been using up to now, but they can make your life much easier. Finally, you'll tackle another useful subject concerning strings: basic string manipulation.

Type Conversion

Earlier in this book you saw that all data, regardless of type, is simply a sequence of bits—that is, a sequence of zeros and ones. The meaning of the variable is determined by the way in which this data is interpreted. The simplest example of this is ...