Variables

Variables are labels that provide a descriptive name for some data that a program can read or modify. You can literally think of a variable as a label.

For example, let's assume there are a number of jars containing different colored jam. How do you know what flavor a specific jar contains? Hopefully, there is a label on the jar that is descriptive of its content.

The labels on the jar can change over time. For example, a jar might contain strawberry jam, but after that's gone it might be filled with peach jam. When the contents of the jar changes, a different label can be used to describe what's in it. Variables work in a similar fashion.

Creating variables

To create a variable, you need to do two things:

• Declare the variable
• Assign a value (data) to the variable

As an example, let's make a variable, foo, and assign it the value bar. The code to do this would be:

foo = "bar"

That single line of code declares a variable and assigns a string value to the variable. If you break it into several...