Scalar Types

Signed integersi8, i16, i32, i64, i128, isize-10, 0, 1_000, 123_i64
Unsigned integersu8, u16, u32, u64, u128, usize0, 123, 10_u16
Floating point numbersf32, f643.14, -10.0e20, 2_f32
Strings&str"foo", "two\nlines"
Unicode scalar valueschar'a', 'α', '∞'
Booleansbooltrue, false

The types have widths as follows:

  • iN, uN, and fN are N bits wide,
  • isize and usize are the width of a pointer,
  • char is 32 bits wide,
  • bool is 8 bits wide.

There are a few syntaxes which are not shown above:

  • Raw strings allow you to create a &str value with escapes disabled: r"\n" == "\\n". You can embed double-quotes by using an equal amount of # on either side of the quotes:

    fn main() {
        println!(r#"<a href="link.html">link</a>"#);
        println!("<a href=\"link.html\">link</a>");
  • Byte strings allow you to create a &[u8] value directly:

    fn main() {
        println!("{:?}", b"abc");
        println!("{:?}", &[97, 98, 99]);
  • All underscores in numbers can be left out, they are for legibility only. So 1_000 can be written as 1000 (or 10_00), and 123_i64 can be written as 123i64.