fn get_first_letters(s: &str) -> String {
let first_letters: String = s
.split_whitespace()
.filter_map(|word| word.chars().next())
.collect();
first_letters
}
fn main() {
let str = "rust javascript php c typescript node.js";
println!("{}", get_first_letters(str));
}
/*
run:
rjpctn
*/