Rust연습_Create a Calculator App러스트로 계산기 만들기-Engineer man

 

main.rs

0.00MB

 

use std::io::{stdin, stdout, Write};

fn read(input: &mut String) {
    stdout().flush().expect("failed to flush");
    stdin().read_line(input).expect("failed to read");
}

fn main() {
    println!("Welcome to engineer man's calculator!");
    println!("--------------------");

    let mut num1 = String::new();
    let mut num2 = String::new();
    let mut operator = String::new();

    println!("What is the first number?:  ");
    read(&mut num1);

    println!("What is the sencond number?:  ");
    read(&mut num2);

    println!("What operation would you like to do? [+-*/]:  ");
    read(&mut operator);

    let num1: f32 = num1.trim().parse().unwrap();
    let num2: f32 = num2.trim().parse().unwrap();
    let operator: char = operator.trim().chars().next().unwrap();

    let operators = String::from("+-*/");

    if !operators.contains(operator) {
        println!("unknown operator");
        return;
    }

    let result = match operator {
        '+' => num1 + num2,
        '-' => num1 - num2,
        '*' => num1 * num2,
        '/' => num1 / num2,
        _ => panic!("error in operator"),
    };

    println!("the result of {} {} {} = {}", num1, operator, num2, result);
}

 

결과

출처
https://youtu.be/RYTMn_kLItw

 

use std::io::{stdin, stdout, Write};
 
fn read(input: &mut String) {
    stdout().flush().expect("failed to flush");
    stdin().read_line(input).expect("failed to read");
}
 
fn main() {
    println!("Welcome to engineer man's calculator!");
    println!("--------------------");
 
    let mut num1 = String::new();
    let mut num2 = String::new();
    let mut operator = String::new();
 
    println!("What is the first number?:  ");
    read(&mut num1);
 
    println!("What is the sencond number?:  ");
    read(&mut num2);
 
    println!("What operation would you like to do? [+-*/]:  ");
    read(&mut operator);
 
    let num1: f32 = num1.trim().parse().unwrap();
    let num2: f32 = num2.trim().parse().unwrap();
    let operator: char = operator.trim().chars().next().unwrap();
 
    let operators = String::from("+-*/");
 
    if !operators.contains(operator) {
        println!("unknown operator");
        return;
    }
 
    let result = match operator {
        '+' => num1 + num2,
        '-' => num1 - num2,
        '*' => num1 * num2,
        '/' => num1 / num2,
        _ => panic!("error in operator"),
    };
 
    println!("the result of {} {} {} = {}", num1, operator, num2, result);
}