How to find the length of a string in Lua?

In Lua, the # operator can be used to obtain the length of a string. Here is an example:

local str = "Hello, World!"
local len = #str
print(len)  -- 输出 13

In the example above, the length of the string variable “str” is returned by #str, then the result is assigned to the variable “len,” and finally the length of the string is printed as 13.