Making all the characters in a string lowercase in Lua

问题

Here is the thing. I am trying to convert a string in lowercase in Lua, but it's not working. I have done this

String = String:lower()

but it doesn't like it. I am sure that is the way to do it, I've seen it done before. A few sites suggest it might be a problem caused by a wrong version of the interpreter.

Any ideas?

回答1:

You're right, this is one of the ways to do it. It would only not work and throw errors if your "String" variable is not a string.

Personally, i usually prefer to use something like..

myString = string.lower(myString)

But its really the same as doing

myString = myString:lower()

assuming that myString is actually a string, however.

The "long" version has one advantage, it actually works if myString is a number, while the second one errors in that case.

来源：https://stackoverflow.com/questions/3202531/making-all-the-characters-in-a-string-lowercase-in-lua