Guided Task: Code Editing Tools
Now that you have seen the power of source code generation and quick fix, you can explore some other Eclipse code editing tools that may be useful as you develop code.
Learning Outcomes
- Explore Eclipse auto-complete
- Explore Eclipse code templates
- Explore Eclipse code formatter
Best Practice: IDE Code Generation
Many IDEs have tools that help with common tasks and some of those tools can help you generate code. You learned how to write these code statements manually in your introductory programming class so that you would fully understand their purpose. Now, you can use Eclipse’s code generation tools to help in writing common statements. A benefit of using code generation tool, besides saving time, is that the code is more likely to be correct. However, you should always test the generated code so make sure that it meets the requirements of the larger program.
Best Practice: Code Formatting and Style
Formatting of code is also important. Well formatted code is easier to read and maintain. Additionally, it easier for others to read - especially if you need help. Most companies have a set of style guidelines that they expect software engineers to follow when working on a code base to ensure that everyone can read and understand code quickly. That is why we have a set of style guidelines for code in CSC216 and enforce those guidelines through the static analysis tool, CheckStyle.
Auto-Complete
Eclipse can fix your simple errors. It can also guess what you want to type via the auto-complete tool. The auto-complete tool is especially handy for remembering class, method, and variable names especially when your code has long or complicated variable or method names.
To use auto-complete, start typing a variable or method name and press Ctrl + Space or Cmd + Space. The auto-complete context menu provides several options for code generation. Select the best option and press Enter to generate the code.
Hint: Any time you want to finish something that you think Eclipse can guess, it’s worth pressing Ctrl + Space or Cmd + Space to see if it does. Eclipse will find things like method names, variables in the current scope, class names, or even make suggestions for a variable you’re declaring! The idea is that you don’t have to remember everything about the program you’re writing. You can select the options with the mouse, but it’s probably faster to use the arrow keys and the Enter key.
Code Templates
Eclipse provides several code templates for commonly used methods and statements.
To use a code template, start typing in the code template keyword and then press Ctrl+Space.
Some keywords for code templates are:
- Typing
mainwill create amainmethod - Typing
sysoutwill create aSystem.out.println()statement. - There are several
forcode templates that will createfor-loops. - The
foreachtemplate will search upward from your current location and find the nearestIterabletype and create an enhancedfor-loop over it. - Typing
/**before a method will generate Javadoc, inferring the parameters to your method. You still have to write the comments that describes what the method does and provide information about the parameters to the method. Don’t write junk! We do read your comments to ensure they describe your code.
Code Formatter
Additionally, Eclipse can help you keep your code well formatted (which is nice for avoiding loss of style points on your programming assignments).
Once you know that your program works, take a look at your code. Methods should be indented within classes, and statements should be indented within methods. If your code does not follow proper indentation let Eclipse help. Press Ctrl + Shift + F (or go to the Source > Format in the menu; Mac users try Cmd + Shift + F).
Customizing Code Templates and the Formatter
If you want to add/edit code templates for the way your code gets formatted, select Window > Preferences (Mac Users select Eclipse > Preferences).
For code templates, select Java > Editor > Templates. Alternatively, start typing “Code templates” in the top text search box to find the menu.
For the formatter, select Java > Code Style > Formatter. Alternatively, start typing “Formatter” in the top text search box to find the menu.
Eclipse defaults to using tabs for indentation. If you want to switch the tab key to enter spaces rather than a tab, do so by editing the style defined in the Formatter properties menu.