Estimated time to complete this lesson: 1 hour. Allow more time to practice and gain deeper understanding.
In this lesson, you will learn about:
To instruct the computer to do what you want it to do, you write a
statement. A program can be created by writing just one statement or more than one statement in a particular sequence.
For example, you can instruct the computer to open a text window and write "Hi, Everyone" in it. To give this instruction, you write the following statement in the Editor:
One ore more statements make up a program in Small Basic. The computer runs a program by reading and understanding each statement line by line.
For example, the above screen shows the statement: TextWindow.WriteLine("Hi, Everyone")
This statement tells the computer to write the line of text, Hi, Everyone, in the text window.
The text window is an object, and you can instruct the computer to perform
operations on that object. For example, you can display the TextWindow object by using the Show operation.
First, type TextWindow.Show() in the Editor, and then click Run on the Toolbar. The result of your program is that the text window appears.
Click the button on the Toolbar.
This is the output you will see:
Similarly, you can hide the TextWindow object by using the Hide operation.
The TextWindow object has a specific set of properties, they are: ForegroundColor, BackgroundColor, Title, CursorTop, CursorLeft, Top, and Left. You can use these properties to change how and where the TextWindow object appears.
TextWindow.Title = "Fun with Small Basic Programming"TextWindow.Left = 300TextWindow.Top = 300TextWindow.BackgroundColor = "Gray"TextWindow.ForegroundColor = "Red"TextWindow.CursorLeft = 30TextWindow.CursorTop = 20
TextWindow.Title = "Fun with Small Basic Programming"
TextWindow.Left = 300
TextWindow.Top = 300
TextWindow.BackgroundColor = "Gray"
TextWindow.ForegroundColor = "Red"
TextWindow.CursorLeft = 30
TextWindow.CursorTop = 20
In the previous screen, we talked about an object called TextWindow. Small Basic contains many more objects. These objects have certain properties, operations, or events attached to them.
To visualise, Properties are something the object has and
Operations are things that the Object does.
Let’s understand the properties and operations of a text window and how we can use them.
In the code that appears here, you set the background color of the TextWindow object to gray and the foreground color to red. Similarly, you specify a title for the text window, the position of the cursor in the text window, and the location
where you want the window to appear on the screen.
To better understand this code, let’s check the output of your program after you run it!
As you see in the output, the default text Press any key to continue… appears in red with a gray background. This is because you set the
BackgroundColor property of the TextWindow to Gray and the
ForegroundColor property to Red.
Notice that the title of the text window is Fun with Small Basic Programming. You specified this title by using the
Title property of the TextWindow object.
The CursorTop property indicates the row position of the cursor in theTextWindow , and the
CursorLeft property indicates the column position of the cursor. You had set these values by using the
CursorTop and CursorLeft properties.
Similarly, the Top property and the Left property indicate the top position and the left position of the TextWindow on the screen.
For the TextWindow object, you can specify the following operations:
Let’s explore some of these operations…
In addition to the Show and Hide operations, you can also perform other actions or operations on the
You have already learned how to show and hide the text window. Now let’s see how you can write text in the TextWindow object.
TextWindow.Write("Hi, everyone!")TextWindow.Write("How are you doing?")
TextWindow.Write("How are you doing?")
You can write text in the text window by using the Write operation of the
As you see, this operation wrote both sentences on the same line with no space between them. But don’t worry: you can use a different operation to show these sentences on separate lines.
TextWindow.WriteLine("Hi, everyone!")TextWindow.WriteLine("How are you doing?")
TextWindow.WriteLine("How are you doing?")
To write the text on separate lines, you use the WriteLine operation.
Write and WriteLine are both operations of the TextWindow object. If you use the WriteLine operation, each line of text appears on a separate line.
Would you like the computer to ask for your name and a friend’s name and then say "Hello" to both of you? Let’s see how to make that happen.
TextWindow.Write("Enter your name: ")name = TextWindow.Read() TextWindow.WriteLine("Hello " + name + ".")
TextWindow.Write("Enter your name: ")
name = TextWindow.Read()
TextWindow.WriteLine("Hello " + name + ".")
If you use the Read operation, the computer reads and remembers what a user has typed. If you use the WriteLine operation, the computer displays the information from the user.
The Read operation of the TextWindow object takes no input. This operation instructs the computer to wait while the user types in text and then presses
ENTER. After the user presses ENTER , the program reads what the user has typed and stores it in memory. You can then use the
Write operation or the WriteLine operation to display the stored information.
Let’s write a program to better understand these operations.
TextWindow.WriteLine("Hi") TextWindow.Pause()TextWindow.Clear() TextWindow.WriteLine("Hello")
After you clear "Hi" away, this is the output you will see:
When the program starts, the computer reads the first statement, which contains the first
WriteLine operation. The computer opens the text window and writes the word “Hi” in it.
The computer then reads the second statement, which contains the Pause operation. The computer pauses and waits for user input.
After the user provides input, the computer reads the third statement, which contains the
Clear operation. The computer clears the word “Hi” from the text window.
Finally, the computer reads the last statement, which contains the second
WriteLine operation. The computer writes the word “Hello” in the text window.
Now you know how to:
Write a program to display a text window and perform the following steps:
To see the solution for this task, go to the Program listing or Import using its Program ID: TJN263.
Under the heading 'The Pause and Clear Operations', the same dot point appears twice.
Further down the page, under the sentence 'This is the output you will see', I think the box there is wrong. It should say Hi.
I'm new at this stuff so hope the observation is correct.
I made those changes. Thanks!
Jibba Jabba edited Revision 8. Comment: refinement in progress