/// Removes all alphabetical letters from the input string slice,
/// returning a new String with letters removed (retaining digits, spaces, and symbols).
///
/// @param input - The source string slice containing alphanumeric and special characters.
/// @return A new String with all alphabetical letters removed.
pub fn remove_letters(input: &str) -> String {
// 1. Convert the string into a Unicode scalar value (char) iterator via .chars()
// 2. Filter the iterator to keep only characters that are NOT alphabetical letters
// 3. Collect the filtered characters into a newly allocated String
input
.chars()
.filter(|c| !c.is_alphabetic())
.collect()
}
fn main() {
// Test string provided
let text = "abc123XYZ456programming789";
// Process the string
let cleaned_text = remove_letters(text);
// Output results
println!("Original: {}", text);
println!("Cleaned: {}", cleaned_text);
}
/*
run:
Original: abc123XYZ456programming789
Cleaned: 123456789
*/
