/**
* Returns the word before the last word from a given string.
* Handles Unicode characters (like Kanji/Hiragana) and various punctuation natively.
* * @param text - The input string to process
* @returns The second-to-last word, or "null" if fewer than two words exist
*/
function getWordBeforeLast(text: string): string {
// Regex breakdown:
// [^\p{L}\p{N}]+ : Match one or more characters that are NOT Unicode Letters or Numbers.
// /u : Enables Unicode support for the property escapes.
const words: string[] = text.split(/[^\p{L}\p{N}]+/u).filter(word => word.length > 0);
if (words.length < 2) {
return "null";
}
// .at(-2) is the idiomatic ES2022+ way to get the second-to-last element
return words.at(-2) ?? "null";
}
function main(): void {
console.log("=== Testing: Get Word Before Last ===\n");
const tests: string[] = [
"python typescript",
" 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"
];
tests.forEach((t: string) => {
const result: string = getWordBeforeLast(t);
console.log(`Input: "${t}"`);
console.log(`Output: ${result}`);
console.log("-".repeat(40));
});
}
main();
/*
OUTPUT:
=== Testing: Get Word Before Last ===
Input: "python typescript"
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
----------------------------------------
*/
