How to comment and uncomment line & block in Eclipse IDE

In this article, we will discuss how to comment & un-comment lines and block of code in Eclipse IDE

At certain times, we want to try-out new things without deleting existing line of code which is already working. Also, it is required to comment & un-comment block of code consisting 3 or more lines of code.

To make this possible, Eclipse IDE provides easy shortcut keys and its respective actions from Menus

 

Shortcut commands in Eclipse IDE:

  • CTRL + / –> to comment single line of code
  • CTRL + / –> the same works to uncomment the same line of code, which is already commented
  • CTRL + SHIFT + / –> to comment block of code consisting of 3 or more lines of code
  • CTRL + SHIFT + \ –> to uncomment block of code, which is already commented

 

Let’s understand each one with simple example in Eclipse IDE:

1. To comment single line of code

Step 1: move to the line where we are interested to comment

Press CTRL + / together

Step 2: press CTRL + / simultaneously

Menu: Source Menu –> Toggle Comment

 

2. To un-comment single line of code

Step 1: move to the line which is already commented

Press CTRL + / together

Step 2: press CTRL + / simultaneously

Menu: Source Menu –> Toggle Comment

Note: if line of code isn’t already commented, then it will comment the code instead of un-commenting

 

3. To comment block of code (3 or more lines of code)

Step 1: select block of code which we are intended to comment

Press CTRL + SHIFT + / together

Step 2: press CTRL + SHIFT + / simultaneously

Menu: Source Menu –> Add Block Comment

 

4. To uncomment block of code (3 or more lines of code)

Step 1: select block of code which is already commented

Press CTRL + SHIFT + \ together

Step 2: press CTRL + SHIFT + \ simultaneously

Menu: Source Menu –> Remove Block Comment

Note: if block of code is already commented, then it will uncomment; otherwise, there won’t be any effects pressing 3 keys together

 

References:

 

Happy Coding !!
Happy Learning !!

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