Is there a way to convert multiple variable declarations to one per line?

Question

In Eclipse, is there an automatic way to convert this:

int myX, myY, myZ;

... to this...

int myX;
int myY;
int myZ;

I thought I could do this from the 'Clean Up' and 'Members Sort Order' preferences, but it does not break up the multiple declarations into one per line. Is there a way to do it?

Edit: To clarify, this is in regards to member variables.

Answer 1

Eclipse does not provide this formatting feature out of the box. You can use Checkstyle plugin to check for this and many more coding standards.

In Checkstyle configuration file, use module MultipleVariableDeclarations like this,

<module name="Checker">
    <module name="TreeWalker">
        <property name="cacheFile" value="target/cachefile"/>
        <property name="tabWidth" value="4"/>
        ...
        <module name="MultipleVariableDeclarations"/>
        ...
    </module>
</module>

If you are OK with command line tool, then astyle and GC GreatCode are two good code formatters.

GC GreatCode is given as C/C++ code formatter but it will format your code in this scenario well.

In GC the option to split variable declaration is -code_split_decl_style

Original code:

String fileName, a, b, c;

With -code_split_decl_style-1 option:

String  fileName,
        a,
        b,
        c;

With -code_split_decl_style-2 option:

String fileName;
String a;
String b;
String c;

You can play around with different command line formatting tools and configurations for various languages in one GUI tool using UniversalIndentGUI.

---

Checkstyle: http://checkstyle.sourceforge.net/

Astyle: astyle.sourceforge.net/

GC GreateCode: http://sourceforge.net/projects/gcgreatcode/

UniversalIndentGUI: universalindent.sourceforge.net/

Answer 2

While I don't know if a single function which does this, you can obtain similar results with a few keystrokes:

1. Highlight the line which contains the multiple variable definitions, and use the Find/Replace function (keystroke: Ctrl-F) to replace the comma-space sequence to a semicolon, space and the type of the variable. Make sure the scope is set to "selected lines" as in the following screenshot:

   

2. Now you'll still have a line with all the variable declarations in a single line. This can be fixed by highlighting the same line and the Source > Format function (keystroke: Shift-Ctrl-F).

   

3. All done, now you have your variables with their respective type, one per line: