Introduction

What is a variable ? A variable is an area into memory to stock data.
Which data ? For example, the color of one car, the best score of one player ... and so on.

Variables in programming are indispensable. We do nothing without variables. So, imagine a program that will ask how old an user is. You wish to print a message if the user is major or minor.

How to do that without variables :-) ? It's symply impossible.

A variable in Gambas owns a datatype. For example, for the age of this user, the value is an interger so, the datatype of this variable will be an interger type. We have in Gambas several datatype, like :

• Integers
• Floats
• Strings
• and so on...

A variable name must follow some rules :

• It must never begin by a digit
• It must never contain any spaces
• It must never contain any accented character

Let's practice

How to use a variable ? Before, we must declare it, i.e "create" it before to use it.

In Gambas, you must declare all your variables. That's a good way to well develop :-) . That allows you to avoid to make some mistakes.

Here is the way to declare one variable :

  DIM variable AS Integer

You can assign a value like that :

DIM var1 AS Interger = 5
DIM myNickname AS String

myNickname = "GarulfoUnix" 'This is another way to assign a value

Right now, let's have a look at how to print this variable by using the PRINT statement :

Examples

' Gambas module file

PUBLIC SUB Main()

  DIM nickname AS String = "GarulfoUnix"

  PRINT "My nickname on internet is " & nickname

END

To concatenate any variables to any strings, we use the & operator.

It's easy, isn't it ? :-)

Work with informations from the user

To get some data from user, we will use the INPUT statement. Here is an example about that :

' Gambas module file

PUBLIC SUB Main()

  DIM nickname AS String

  PRINT "What is your nickname ?"
  INPUT nickname

  PRINT "Your nickname is " & nickname

END

When the program will arrive on this line :

INPUT nickname

It will stop to wait the data from user until user will press the Return key.