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Part 1—Requirements
The tasks to perform to extend Lab 7 to a general application are easy.
One simplification is that the input will be capital lettes. This saves
the hassle of having to convert to capitals, which isn't that hard, but it is not
very instructive.
Expect to perform the following operations to create your application.
- To get an idea how much time is needed to solve this extra credit problem, add a comment
in the head of your HTML code for the date and EXACT time to the minute
shown on your computer right now. Comments
are placed inside of <!-- ... --> tags.
- Restructure the page. Notice that the page changes organization. The command button
is now above the image and has a new value. A text window must be created. And the text surrounding the two
must be changed.
- The full alphabet of pictures must be downloaded from About.com into the
exc01 folder. Consult the instructions
for Lab 07 if you have forgotten the URL for the site. Don't forget to get the "extra" images for
the letters J and Z.
- Two new variables must be declared at the start of the JavaScript section:
text="" and elapsed=0.
- The onclick event handler for the button must be changed to perform two operations:
- Assign the value from the text window to the variable text
- Call the spell( ) function, as before. Remember event handlers are Javascript so semicolons(;) are
required after each statement.
- The spell( ) function must be changed. First, it will not have any parameters. Second the processing
will change to use a for loop. (Keep the last line displaying the folded hands.)
Loops are discussed in Chapter 20 of the book, and were introduced by D. A. Clements in her lecture.
The loop will iterate through the letters of the word the user typed
in. The user's input will be stored in the variable text. For
each letter, the show( ) function will be called.
If the loop variable is, say, j, then the iteration starts at 0. It ends when j is less than
text.length, and after each iteration, j should increase by 1, i.e. j++. The WFI is
recommended
Keep in mind that the body of a loop is enclosed in braces, { }.
At this point, nearly everything is done.
Last items to consider.
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