Deletion means erasing text and not saving it in the kill ring. For the most part, the Emacs commands that delete text are those that erase just one character or only whitespace.
We have already described the basic deletion commands <DEL>
delete-forward-char), and C-d (
See Erasing. With a numeric argument, they delete the specified
number of characters. If the numeric argument is omitted or one,
<DEL> and <delete> delete all the text in the region if it is
active (see Using Region).
The other delete commands are those that delete only whitespace
characters: spaces, tabs and newlines. M-\
delete-horizontal-space) deletes all the spaces and tab
characters before and after point. With a prefix argument, this only
deletes spaces and tab characters before point. M-<SPC>
just-one-space) does likewise but leaves a single space before
point, regardless of the number of spaces that existed previously
(even if there were none before). With a numeric argument n, it
leaves n spaces before point if n is positive; if n
is negative, it deletes newlines in addition to spaces and tabs,
leaving -n spaces before point. The command
acts like a more flexible version of
does different things if you call it repeatedly in succession.
The first call acts like
just-one-space, the next removes
all whitespace, and a third call restores the original whitespace.
C-x C-o (
delete-blank-lines) deletes all blank lines
after the current line. If the current line is blank, it deletes all
blank lines preceding the current line as well (leaving one blank line,
the current line). On a solitary blank line, it deletes that line.
delete-indentation) joins the current line and the
previous line, by deleting a newline and all surrounding spaces, usually
leaving a single space. See M-^.
delete-duplicate-lines searches the region for
identical lines, and removes all but one copy of each. Normally it
keeps the first instance of each repeated line, but with a C-u
prefix argument it keeps the last. With a C-u C-u prefix
argument, it only searches for adjacent identical lines. This is a
more efficient mode of operation, useful when the lines have already
been sorted. With a C-u C-u C-u prefix argument, it retains
repeated blank lines.