jak spojit dva
// using 2 variables
let new_string = format!("{}{}", first_string, second_string);
// using 2 literals
let new_string = format!("{}{}", "first string ", "second string");
rzi zřetězené struny
let text1 = "hello".to_owned();
let text2 = text1 + " world";
println!("{}", text2);