Get the value of window-local variable {varname} in window {winnr} in tab page {tabnr}. The {varname} argument is a string. When {varname} is empty a dictionary with all window-local variables is returned. When {varname} is equal to "&" get the values of all window-local options in a Dictionary. Otherwise, when {varname} starts with "&" get the value of a window-local option. Note that {varname} must be the name without "w:". Tabs are numbered starting with one. For the current tabpage use getwinvar(). {winnr} can be the window number or the window-ID. When {winnr} is zero the current window is used. This also works for a global option, buffer-local option and window-local option, but it doesn't work for a global variable or buffer-local variable. When the tab, window or variable doesn't exist {def} or an empty string is returned, there is no error message. Examples:

:let list_is_on = gettabwinvar(1, 2, '&list')
:echo "myvar = " .. gettabwinvar(3, 1, 'myvar')

To obtain all window-local variables use:

gettabwinvar({tabnr}, {winnr}, '&')

Can also be used as a method:

GetTabnr()->gettabwinvar(winnr, varname)