String

String is the standard heap-allocated growable UTF-8 string buffer:

1. fn main() {
2. let mut s1 = String::new();
3. s1.push_str("Hello");
4. println!("s1: len = {}, capacity = {}", s1.len(), s1.capacity());

6. let mut s2 = String::with_capacity(s1.len() + 1);
7. s2.push_str(&s1);
8. s2.push('!');
9. println!("s2: len = {}, capacity = {}", s2.len(), s2.capacity());

11. let s3 = String::from("🇨🇭");
12. println!("s3: len = {}, number of chars = {}", s3.len(),
13. s3.chars().count());
14. }

String implements Deref, which means that you can call all str methods on a String.

• len() returns the size of the String in bytes, not its length in characters.
• chars() returns an iterator over the actual characters.