easy to understand, well made

Is using sb.Grow before a loop always going to be more performant than using buffer.WriteString within a loop? I'm not familiar w/ Golang compiler internals nor it's optimizations, but I kind of assume there could less memory allocation ops in your solution, if compiler doesn't translate both versions to the same machine code.

Oh my god what is this!? i might neet to throw this in chatgpt to understand

of course. only change constants.

but the testcases are against that

and this code may be used on other planets

Short-curcuiting is mostly used for defining default values or making decisions. Ternary operator is preferable here since it's just a simple return, furthermore it's just a much clearer code to read... 🤓

my god...

I don't think this null is necessary for this problem.

easy to maintence and reality in development of the game like this

very readable

@davorpa If you read the docs, it shows that has the null check built into it.

if (locale == null) {
throw new NullPointerException();
}

do you know the concept of null-safe methods? null is not same as empty

It's no need to check for empty string, because .toUpperCase contains this condition: https://www.javatpoint.com/java-string-touppercase

why try hard ?