- Get Ready to Program
- What a Computer Program Does
- Common Programming Misconceptions
- Many Programs Already Exist
- Programmers Are in Demand
- The Real Value of Programs
- Users Generally Don't Own Programs
- Giving Computers Programs
- Your First Program
- Clarifying Comments
- Entering Your Own Program
- Summary
- Q&A
- Workshop
This chapter is from the book
This chapter is from the book
This chapter is from the book
Entering Your Own Program
You’re now ready to type and run your own program from scratch. The program will be simple. The goal here is to get you used to using the editor.
Try it Yourself
Follow these steps to create your own program:
- In your text editor, select File and then New File to create a brand-new document.
Type the program in Listing 1.2 into the editor. Be careful that you type the program exactly as you see it in the listing. If you make a typing mistake, you will not be able to run the program. The program is a little bit complicated, but if you type it as is, you should have a working program. Notice that both styles of comments are used in the program.
LISTING 1.2 Type your first program into the editor.
<!DOCTYPE html> <html> <head> <script> /* This is the function that gets called when the user clicks the button on the main page */ function displayAnswer() { document.write("Just 24 1-hour lessons!"); } </script> </head> <body> <h1>My First Program</h1> <p id="demo">How long will it take for me to learn to program?.</p> <button type="button" onclick="displayAnswer()">How many hours?</button> </body> </html>Save the program as text only, and give it a name with an .html ending. I named mine TYBeginProgram1.html. After you save the program, either double click the file’s icon in your explorer or open the file in your web browser. You should see the web page shown in Figure 1.3 to start and in Figure 1.4 when you click the button.
FIGURE 1.3 With less than two dozen lines of code, you’ve created a simple web page, complete with a button for the visitor to click.
FIGURE 1.4 Once you click the button on your web page, you get a new page with more information. Awesome interactivity, right?
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If your program contained an error, the page would not show up like the ones in Figures 1.3 and 1.4. You would have to work through your version line-by-line to see where the error might be.