find the first index of a substring in a string in rust

main.rs
fn main() {
    let my_string = String::from("Welcome to Rust Programming");
    let my_substring = "Rust";
    
    if let Some(i) = my_string.find(my_substring) {
        println!("Index of first substring: {}", i); // 11
    } else {
        println!("Substring not found");
    }
}
286 chars
11 lines