[HELP]Characters

[AncienT]

 

How to allow all the letters and the character you want in lua, for example I want that only letters can be written and the character "_"

[Dimos7]

You want it for gui text or something? 

[Skully]

Use string.find to check what characters are in a string.

[Addlibs]

You could using string.match to ensure that from start to end, only letters (%a) and the underscore (_) symbol are allowed. E.g. 

return string.match(str, "^[%a_]+$") == str

^ matches beginning of string, [...] makes a set, %a includes all letters (uppercase and lowercase) into the set, _ adds underscore into the set, the + means it can match more than once, and $ matches the ending of the string. The function returns the matched string, which should be identical to the input string since we're matching from start to end. It returns a nil if nothing matched, that is, the input string wasn't from start to end only letters and underscores. It is very lenient and allows names even like Test__, or __john_sMiTh__, etc. No enforcement of where the underscore can be, how much can there be, and no enforcement of capitals.

If you want it to be a little more rigid, for example, that the underscore must separate two different words made of letters, you could use the following

return string.match(str, "^%a+_%a+$") == str

and if you want to enforce capital letters at the beginning of these two words,

return string.match(str, "^%u%l+_%u%l+$") == str -- must begin with capital letter and all subsequent must be lowercase

return string.match(str, "^%u%a+_%u%a+$") == str -- must begin with capital letter and all subsequent can be either case

 

Edited November 29, 2018 by MrTasty