How do I record a macro to toggle comments on a line?

Explanation

This macro adds a // comment prefix to the beginning of the current line and moves down. For uncommenting, record a separate macro that removes the prefix.

How it works

Comment macro:

1. qa — start recording to a
2. I// — insert // at line start
3. <Esc>j — return to normal mode, move down
4. q — stop recording

Uncomment macro:

1. qb — start recording to b
2. ^3x — go to first non-blank, delete 3 chars (// )
3. j — move down
4. q — stop recording

Example

5@a comments 5 lines. 5@b uncomments them.

Tips

• Adjust the prefix for different languages (#, --, /* */)
• The vim-commentary plugin handles this automatically
• Use visual mode + I// <Esc> for block commenting
• Consider using norm I// with ranges for one-off use