&str

&str is a primitive string type in Rust. Another name for this type is 'string slice'. It is called a string slice because it is a slice of a string.

Slices are references to the original string, so they don't own the data. This prevents unnecessary copying of data.

Every type of string in Rust is utf-8 encoded. That means we can initialize a string in any languages. We can also include emoticons. Now let's see how it's done.

#![allow(unused)]
fn main() {
    let one_piece: &str = "I am gonna be the King of the Pirates! ⚓🚢";
    let one_pisu: &str = "海賊王に俺はなる！ ⚓🚢";

    println!("{}\n", one_piece);
    println!("{}", one_pisu);
}

When you extract a portion of a string which is String or a &str type, you create a &str type. The extraction is done with specifying the start and end index of the string in square brackets.

#![allow(unused)]
fn main() {
    let greeting: &str = "Hello, world!";
    let sub_str = &greeting[0..5];

    println!("{}", greeting);
    println!("{}", sub_str);
}