Rust Brain Teasers/

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Puzzle 2: Explanation

Puzzle 2: Explanation

Let’s find out how Rust handles string operations while taking input from users.

We'll cover the following...

Test it out

Hit “Run” to see the code’s output.

use std::io::stdin;

fn main() {
    println!("What is 3+2? Type your answer and press enter.");
    let mut input = String::new();
    stdin()
        .read_line(&mut input)
        .expect("Unable to read standard input");

    if input == "5" {
        println!("Correct!");
    } else {
        println!("Incorrect!");
    }

    println!("{:#?}", input);
}
What is 3 + 2? Not 5!

Explanation

Normally, 3+2 would equal 5, but that’s not how Rust handles strings! To find out why, add the following line to the end of the program:

println!("{:#?}", input);

With this new line, we’ll be able to see the full-string Rust returns from stdin.

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