items = {
{'z'},
{'a'},
},
print(table.sort(items, function( a,b ) return a < b end))
--log (https://rextester.com/l/lua_online_compiler)
Error(s), warning(s):
lua5.3: ...sktop/rextester_linux_2.0/usercode/1536613711/source.lua:8: bad argument #1 to 'sort' (table expected, got nil)
stack traceback:
[C]: in function 'table.sort'
...sktop/rextester_linux_2.0/usercode/1536613711/source.lua:8: in main chunk
[C]: in ?