Rust - string

rust에서 문자열은 compound type이다.

from() and into() come from the From and Into traits respectively: they are for losslessly converting between arbitrary types, not just strings.

Into is automatically implemented if you implement the From trait, so normally (unless coherence rules prevent it) you would only ever implement the From trait.

to_string comes from the ToString trait. This trait is automatically implemented for all types which implement the Display trait. You would never implement ToString directly. In this case the reason for two traits is that Display is the more fundamental one, it's more powerful and more efficient because it doesn't require allocating a String. However ToString can be more convenient to use for the caller.

let s = "String"; // type &str , .to_string()으로 변경 가능
let ss = String::from("String!"); // type std::string::String

문자열 합치기

let h = String::from("Hello ");
let w = String::from("World!");
let s = h + &w // concat(self, &String) h -> s, ownership
println!("{}", s);

8개 정도 문자열

    // owned type
    // String 가변형 속성에 사용할 때 편리함. 자기 데이터를 갖고있는 
    
    let my_name = "David".to_string() // String
    let other_name = Srting::from("David2");
    // growable + shrinkable
    let mut my_other_name = "David3".to_string();
    my_other_name.push('!');


    // &str "string slice"
    

fn main() {
    //String
    //.capacity
    //.push 이건 캐릭터
    //.push_str 이건 문자열
    //.pop
    // with_capacity allocation
    //.len
    let mut my_name = "David".to_string();
    my_name.push('!');
    println!("My name is {}", my_name);
    let mut aa = String::with_capacity(26); // 바이트 할당 reallocation 없음
}


export const _frontmatter = {"title":"Rust - string","author":"vlwkaos","tags":[],"aliases":[],"created":"2022-02-06:14:53:38"}