格式化输出

本课属于 Coddy Rust 学习旅程的“基础知识”单元。第 36 课，共 75 课。

挑战

入门

修改输出，使其始终打印保留两位小数的浮点数值。要做到这一点，请使用 {:.2} 符号：

let num = 1.5576734;
println!("This is rounded: {:.2}", num);
// Output: This is rounded: 1.56

亲手试试

use std::io;

fn main() {
    println!("Calculator App");

    let mut input_num1 = String::new();
    let mut input_num2 = String::new();
    io::stdin().read_line(&mut input_num1).unwrap();
    io::stdin().read_line(&mut input_num2).unwrap();
    let num1: f64 = input_num1.trim().parse().unwrap();
    let num2: f64 = input_num2.trim().parse().unwrap();
    let sum = num1 + num2;
    let difference = num1 - num2;
    let product = num1 * num2;
    let quotient = num1 / num2;
    println!("Sum: {}", sum);
    println!("Difference: {}", difference);
    println!("Product: {}", product);
    println!("Quotient: {}", quotient);
}