Conversion between String, str, Vec<u8>, Vec<char> in Rust

string-conversion.rs

use std::str;

fn main() {
  // -- FROM: vec of chars --
  let src1: Vec<char> = vec!['j','{','"','i','m','m','y','"','}'];
  // to String
  let string1: String = src1.iter().collect::<String>();
  // to str
  let str1: &str = &src1.iter().collect::<String>();
  // to vec of byte
  let byte1: Vec<u8> = src1.iter().map(|c| *c as u8).collect::<Vec<_>>();
  println!("Vec<char>:{:?} | String:{:?}, str:{:?}, Vec<u8>:{:?}", src1, string1, str1, byte1);

  // -- FROM: vec of bytes --
  // in rust, this is a slice
  // b - byte, r - raw string, br - byte of raw string
  let src2: Vec<u8> = br#"e{"ddie"}"#.to_vec();
  // to String
  // from_utf8 consume the vector of bytes
  let string2: String = String::from_utf8(src2.clone()).unwrap();
  // to str
  let str2: &str = str::from_utf8(&src2).unwrap();
  // to vec of chars
  let char2: Vec<char> = src2.iter().map(|b| *b as char).collect::<Vec<_>>();
  println!("Vec<u8>:{:?} | String:{:?}, str:{:?}, Vec<char>:{:?}", src2, string2, str2, char2);

  // -- FROM: String --
  let src3: String = String::from(r#"o{"livia"}"#);
  let str3: &str = &src3;
  let char3: Vec<char> = src3.chars().collect::<Vec<_>>();
  let byte3: Vec<u8> = src3.as_bytes().to_vec();
  println!("String:{:?} | str:{:?}, Vec<char>:{:?}, Vec<u8>:{:?}", src3, str3, char3, byte3);

  // -- FROM: str --
  let src4: &str = r#"g{'race'}"#;
  let string4 = String::from(src4);
  let char4: Vec<char> = src4.chars().collect();
  let byte4: Vec<u8> = src4.as_bytes().to_vec();
  println!("str:{:?} | String:{:?}, Vec<char>:{:?}, Vec<u8>:{:?}", src4, string4, char4, byte4);
}

My favourite about Rust would be transforming String using let char3: Vec<char> = src3.chars().collect::<Vec<_>>(); into Vec<char>, it makes so much sense!

Just found that an alternative way of converting String to Vec is this String::into_bytes().

pub fn into_bytes(self) -> Vec<u8, Global> ⓘ

Converts a String into a byte vector.

This consumes the String, so we do not need to copy its contents.

awesome, thanks!

@jimmychu0807 thank you my friend :)

Are you god?

Thanks, super useful collection of examples!

thank you dear sir !

let byte1: Vec = src1.iter().map(|c| *c as u8).collect::<Vec<_>>();

This won't work for multi-byte characters (like '你', '漢', '😊', 'م', 'Ω').

let byte1: Vec = src1.iter().map(|c| *c as u8).collect::<Vec<_>>();

This won't work for multi-byte characters (like '你', '漢', '😊', 'م', 'Ω').

That's what I'm worrying about