String

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

fn main() {
let mut s1 = String::new();
s1.push_str("Hello");
println!("s1: len = {}, capacity = {}", s1.len(), s1.capacity());
let mut s2 = String::with_capacity(s1.len() + 1);
s2.push_str(&s1);
s2.push('!');
println!("s2: len = {}, capacity = {}", s2.len(), s2.capacity());
let s3 = String::from("🇨🇭");
println!("s3: len = {}, number of chars = {}", s3.len(),
s3.chars().count());
}
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

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

Speaker Notes

  • len returns the size of the String in bytes, not its length in characters.
  • chars returns an iterator over the actual characters.
  • String implements Deref<Target = str> which transparently gives it access to str’s methods.