An unsigned integer is a whole number that cannot be negative. In Rust, unsigned integer types include u8, u16, u32, u64, u128, and usize. By contrast, a signed integer can be negative, zero, or positive. section 1.3
The number after `u` tells you how many bits the type uses. A bit can be 0 or 1, and each bit position is worth twice as much as the previous one. More bits allow larger numbers: `u8` can hold values up to 255, while `u16` can hold values up to 65,535. section 1.3
fn main() {
let my_number: u8 = 100; #1
println!("{}", my_number as char);
}
The `: u8` annotation tells Rust that `my_number` has the unsigned type `u8`. The example then casts that value to a character. section 1.3
