It is easy to create a vector of hard-coded &str strings, but sometimes, especially for examples, I need a vector of hard-coded String values. I need that in order to demonstrate how to deal with a vector of values I read from a file that are going to be String values.

There are two options. Either create a vector and call to_string manually on each one of the elements, or uses an iterator and call to_string on each one of them.

Create a vector of str: Vec<&str>

let colors = vec!["blue", "red", "green", "yellow"];

Create a vector of String: Vec<String> using to_string on each on of them

let colors = vec![
    "blue".to_string(),
    "red".to_string(),
    "green".to_string(),
    "yellow".to_string(),
];

Create a vector of String: Vec<String> using to_string in a map

let colors = vec!["blue", "red", "green", "yellow"]
    .into_iter()
    .map(|str| str.to_string())
    .collect::<Vec<String>>();

Using the Turbofish syntax to let collect know the type of the items.

The full code

examples/hard-coded-vector-of-strings/src/main.rs

fn main() {
    let colors = vec!["blue", "red", "green", "yellow"];
    println!("{:?}", colors);

    let colors = vec![
        "blue".to_string(),
        "red".to_string(),
        "green".to_string(),
        "yellow".to_string(),
    ];
    println!("{:?}", colors);

    let colors = vec!["blue", "red", "green", "yellow"]
        .into_iter()
        .map(|str| str.to_string())
        .collect::<Vec<String>>();
    println!("{:?}", colors);
}

The output is the same in each case:

["blue", "red", "green", "yellow"]
["blue", "red", "green", "yellow"]
["blue", "red", "green", "yellow"]