/**
* Returns the word before the last word.
* Uses Rust's native Unicode-aware char methods to handle international text.
*/
fn get_word_before_last(text: &str) -> String {
// 1. Split the string by any character that is NOT alphanumeric.
// Rust's `is_alphanumeric` handles Unicode (Kanji, Cyrillic, etc.) natively.
// 2. Filter out empty strings caused by multiple spaces or punctuation.
// 3. Collect into a Vector of string slices.
let words: Vec<&str> = text
.split(|c: char| !c.is_alphanumeric())
.filter(|s| !s.is_empty())
.collect();
// Check if we have at least two words
if words.len() < 2 {
return "null".to_string();
}
// Return the second to last word
words[words.len() - 2].to_string()
}
fn main() {
println!("=== Testing: Get Word Before Last ===\n");
let tests = vec![
"python rust",
" 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 {
let result = get_word_before_last(t);
println!("Input: \"{}\"", t);
println!("Output: {}", result);
println!("{}", "-".repeat(40));
}
}
/*
OUTPUT:
=== Testing: Get Word Before Last ===
Input: "python rust"
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
----------------------------------------
*/
