Set the register {regname} to {value}. If {regname} is "" or "@", the unnamed register '"' is used. In |Vim9-script| {regname} must be one character. {value} may be any value returned by |getreg()| or |getreginfo()|, including a |List| or |Dict|. If {options} contains "a" or {regname} is upper case, then the value is appended. {options} can also contain a register type specification: "c" or "v" |characterwise| mode "l" or "V" |linewise| mode "b" or "" |blockwise-visual| mode If a number immediately follows "b" or "" then this is used as the width of the selection - if it is not specified then the width of the block is set to the number of characters in the longest line (counting a as 1 character). If {options} contains no register settings, then the default is to use character mode unless {value} ends in a for string {value} and linewise mode for list {value}. Blockwise mode is never selected automatically. Returns zero for success, non-zero for failure. Note: you may not use |List| containing more than one item to set search and expression registers. Lists containing no items act like empty strings. Examples: :call setreg(v:register, @) :call setreg('', @%, 'ac') :call setreg('a', "1\n2\n3", 'b5') :call setreg('"', { 'points_to': 'a'}) This example shows using the functions to save and restore a register: :let var_a = getreginfo() :call setreg('a', var_a) or: :let var_a = getreg('a', 1, 1) :let var_amode = getregtype('a') .... :call setreg('a', var_a, var_amode) Note: you may not reliably restore register value without using the third argument to |getreg()| as without it newlines are represented as newlines AND Nul bytes are represented as newlines as well, see |NL-used-for-Nul|. You can also change the type of a register by appending nothing: :call setreg('a', '', 'al') Can also be used as a |method|, the base is passed as the second argument: GetText()->setreg('a')