Variables

Introduction

What is a variable? A variable stores an item that can change. e.g. "Car" can be changed to "Cars", 1 can become 567

Variables in programming are indispensable. We can do nothing without variables. So, imagine a program that asks how old a user is. You may wish to print a message depending on the age of the user.

There are many variables types in Gambas, let's start with a few simple ones.

• Integers - Whole numbers e.g. 1, 14, 897

• Float - Numbers with decimals e.g. 1.2, 10.115, 0.5, 3.142

• String - Text e.g. "What is your name?", "Apple"

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? Firstly we must declare it, i.e. "create" it before we can use it.

In Gambas, you must declare all your variables. This is good practice and will help avoid making some mistakes.

This is one way to declare a variable:

You can assign a value like this:

Let's have a look at how to print a variable by using the PRINT command:

To concatenate (join together) any String variables, we use the & operator.

It's easy, isn't it?

Work with information from the user

To get some data from the user, we will use the InputBox command. http://gambaswiki.org/wiki/comp/gb.form/inputbox. Here is an example:

When the program arrives at this line:

It will stop and wait for the data from user and continue when the user presses the Return (or Enter) key.

Last edited by Charlie Ogier 03/11/2018