Task 3 - LEarning about Inputs and Variables

Theory

So far we have learnt to output a message. Now we are going to look at inputting and then getting the computer to output it. When we input data the computer stores this in an area of memory. We DECLARE the area of memory by setting up a DIM statement which creates the area. We then assign that area with a NAME known as a VARIABLE. Each variable has a data type assigned so we tell the computer what type of data will be stored in that area.

Example

Dim FirstNumber as Integer

Dim - Declare or make an area

FirstNumber - Call the area Firstnumber (this will be where we store the Firstnumber variable

As Integer - We will be storing whole numbers in that area

We then write code to get the user to input a number which we then store in that area. This is known an a Variable.

Example

FirstNumber = InputBox("Please enter a number")

FirstNumber - is the area we made to store the number

InputBox - produces a box for the user to type in the number which then gets stored in the area FirstNumber

Please read this link for further information on variables

Extension

• Make buttons to Subtract, Multiply and Divide the two numbers entered. (HINT - If your answers is coming out correct for these then have a look at the next page and you may need to change the data type from Integer to store a decimal).

• Change the back colour and fore colour of the buttons.

• Change the back colour and fore colour of the form

Extra Practice of these skills

1. Calculate the Average of the number entered. Extend to add more than two numbers

2. Write an application in Visual Basic that calculates the area of a circle.

Area = radius x radius x pi (pi = 3.142)

Add features to calculate the area of a triangle and a rectangle.

• (HINT - If your answers is coming out correct for these then have a look at the next page and you may need to change the data type from Integer to store a decimal).