Beginning Programming ALL-IN-ONE DESK REFERENCE FOR DUMMIES®

Chapter III.1. Structures and Arrays

All programs need to store data. If a program asks the user to type in her name, the program needs to store that name somewhere so it can find the name again. The most common way programs store data is to dump data in a variable.

Unfortunately, a variable can only hold one chunk of data at a time, such as a single number or a name. If you want to store a person's first and last name along with their age, you have to create three separate variables, such as

Dim FirstName as String
Dim LastName as String
Dim Age as Integer

Creating separate variables to store related data can be like carrying around three separate wallets with one wallet holding your cash, a second wallet holding your credit cards, and a third wallet holding your driver's license. Just as it's more convenient to store your cash, credit cards, and driver's license in a single wallet, so it's also more convenient to store related data in a single variable. Two ways to store related data in one place are structures and arrays.

Warning

Because structures and arrays are two other ways to store data, they're often called data structures.

Using Structures

A structure (also dubbed a record in some programming languages) does nothing more than group separate variables together. So rather than create and try to keep track of three separate variables, a structure lets you store multiple variables within another variable. So if you had three variables — FirstName, LastName, and Age — you could store ...