Vim delete blank lines

What command can I run to remove blank lines in Vim?

Solution 1:

:g/^$/d

:g will execute a command on lines which match a regex. The regex is 'blank line' and the command is :d (delete)

Solution 2:

Found it, it's:

g/^\s*$/d

Source: Power of g at vim wikia

Brief explanation of :g

:[range]g/pattern/cmd

This acts on the specified [range] (default whole file), by executing the Ex command cmd for each line matching pattern (an Ex command is one starting with a colon such as :d for delete). Before executing cmd, "." is set to the current line.

Solution 3:

:v/./d

or

:g/^$/d

or

:%!cat -s