// Kotlin’s String is based on the JVM's UTF-16 representation,
// which handles characters like 世 and 界 natively.
/**
* Returns the word before the last word.
* Uses Unicode-aware regex to handle international scripts and punctuation.
*/
fun getWordBeforeLast(text: String): String {
// Regex breakdown:
// [^\p{L}\p{N}]+ : Match one or more characters that are NOT Unicode Letters or Numbers.
// .filter { it.isNotEmpty() } : Remove empty strings from leading/trailing delimiters.
val words = text.split(Regex("[^\\p{L}\\p{N}]+"))
.filter { it.isNotEmpty() }
return if (words.size < 2) {
"null"
} else {
// .let or simple indexing is idiomatic;
// using size - 2 to get the second to last element.
words[words.size - 2]
}
}
fun main() {
println("=== Testing: Get Word Before Last ===\n")
val tests = listOf(
"python kotlin",
" many spaces here now ",
"OneWord",
"",
" ",
"Hello, world!",
"Tabs\tand\nnewlines work too",
"Unicode 世界、こんにちは",
"Ends with punctuation.",
"Multiple words, with punctuation, here!",
"state-of-the-art program example"
)
for (t in tests) {
val result = getWordBeforeLast(t)
println("Input: \"$t\"")
println("Output: $result")
println("-".repeat(40))
}
}
/*
OUTPUT:
=== Testing: Get Word Before Last ===
Input: "python kotlin"
Output: python
----------------------------------------
Input: " many spaces here now "
Output: here
----------------------------------------
Input: "OneWord"
Output: null
----------------------------------------
Input: ""
Output: null
----------------------------------------
Input: " "
Output: null
----------------------------------------
Input: "Hello, world!"
Output: Hello
----------------------------------------
Input: "Tabs and
newlines work too"
Output: work
----------------------------------------
Input: "Unicode 世界、こんにちは"
Output: 世界
----------------------------------------
Input: "Ends with punctuation."
Output: with
----------------------------------------
Input: "Multiple words, with punctuation, here!"
Output: punctuation
----------------------------------------
Input: "state-of-the-art program example"
Output: program
----------------------------------------
*/
