Eclipse allows us to use “Ctrl + / “to comment multiple lines with “//” after highlighting them. Press “Ctrl + / ” again to uncomment.
“Ctrl + Shift + / ” will comment multiple lines with “/* */”. Use “Ctrl + Shift + \ ” to uncomment.
Some people suggest that “/* */ does not nest and can cause errors”, so it’s better to use just “//” on each line.
References:
(1) Tutorial: http://avajava.com/tutorials/lessons/how-do-i-comment-out-a-section-of-code.html
(2) StackOverflow: http://stackoverflow.com/questions/2449304/in-java-what-is-the-syntax-for-commenting-out-multiple-lines