Vim

" Insert text in the end of each line
" s/ - substitute.
" $ - the end of the line.
" / - change it to.
" , - a comma.
:%s/$/,

" Lowercase line
Vu

" Find char backwards
F<char>

" Delete backwards until char
dT<char>

" Visually select until char
v/<char><return>

" Delete all lines in file
:%d

" Yank two inner words
" Yanks first and second words (with the trailing space) in the unnamed register
y2aw

" Delete until start of line
d0

" Yank entire file
:%y+

" Select entire block
Vat

" Visually select until end of line
v$

" Visually select paragraph or function
V}

" See whats in a buffer
" See insides of q buffer
:echo @q

" See registers
:registers

" Delete until end of file
VGx

" Visually select block
V%

" Start recording macro
" Record to register d
qd

" Delete char under cursor
x

" Yank inside tag. Can yank an XML tag for example
yat

" Make multi line search. https://vim.fandom.com/wiki/Search_across_multiple_lines
" Will carry over to new line
\_s

" Inclusive search
/foo/e

" Delete until searched string. Won't delete string itself.
d/string

" Search and replace
:%s/<search>/<replace>/g

" Run command on startup
" Run ':Goyo' on startup. Put it in .vimrc
autocmd VimEnter * Goyo"

" Insert text at start of each line in file
" Insert // at start of each line in file
:%s!^!//!

" Replay last macro
@@

" Delete until character
df<char>

" Centre current line
zz

" Put results of command into a register
" In normal mode, will put results of d$ command into _ (black hole register)
"_d$

" Run macro on whole file
:%normal @x " will run macro x