How to comment uncomment single line and block of code in Java - Eclipse Tips Tricks

Knowing Eclipse shortcut to comment and uncomment single line or block
of code can save you lot of time while working in Eclipse. In fact I highly
recommend every Java programmer to go through these top
30 Eclipse shortcut and  10
java debugging tips in Eclipse for improved productivity.  If you are Java
programmer, coding in Eclipse and want to comment and uncomment single line or
block of code quickly you can either use ctrl + / to comment
a single line and subsequently uncomment a commented line. If you want to
comment a block of code or a complete method, you have two option you can
either line comment (//) all those selected lines or block
comment (/* */) those lines. For line comment multiple line, select
multiple line and press ctrl + /, it will put // in front of every
line. For block commenting in Eclipse, first select all the lines or code block
you want to comment and then enter ctrl+shift+/ it will put /* on first line
and */ on last line. Here is better illustrated example of commenting and
uncommenting Java code in Eclipse IDE :

Eclipse shortcut to comment one line or
block code in Java

Suppose I have a following method :

public void
printHello(){

    System.out.println("HelloWorld");

}

and I want to comment line which is printing HelloWorld, just put
the courser on that line and type ctrl+/ , you will see following line :

public void printHello(){

//
   System.out.println("HelloWorld");

}

If you want to uncomment that same line, keep the cursor on same line and
type again ctrl+/, it will uncomment that line.

If you want to comment whole method , first select whole method and then
type ctrl+/, this will line comment all selected line as shown below :

//public void printHello(){

//  
 System.out.println("HelloWorld");

//}

If you want to block comment whole block than type ctrl
+ shift + / and it will put  /*
and */ on first and last line, as shown below :

/*public void printHello(){

    System.out.println("HelloWorld");

}*/

This Eclipse shortcut for commenting and uncommenting Java code
will surely help you save few keystrokes and improve your speed while working
in Eclipse. To learn more Eclipse comments short cuts see Top
30 Eclipse keyboard Shortcuts for Java programmer.

Other Eclipse tutorials for Java programmer

How
to setup Java remote debugging in Eclipse

Top
10 Eclipse debugging tips for Java programmer

10
tips to write better code comments

Eclipse
shortcut for remove all unused imports in Java

Eclipse
shortcut to print System.out.println in Java

Source:http://javarevisited.blogspot.com/2012/12/eclipse-shortcut-to-comment-uncomment.html