/Match-and-Input

Primary LanguageRust

Match Statement

Match Operator is a powerful operator which lets you match a particular value with a range of values and execute some operations or code for it. It is similar to switch() in Java.

let num = 70;
match num {
    1 => println!("one"),
    2 => println!("two"),
    3 | 4 | 5 => println!("3-5"),
    6..=10 => println!("6-10"),
    _ => println!("Invalid"),
}
enum Coin {
    Penny,
    Nickel,
    Dime,
    Quarter,
}

fn value_in_cents(coin: Coin) -> u8 {
    match coin {
        Coin::Penny => 1,
        Coin::Nickel => 5,
        Coin::Dime => 10,
        Coin::Quarter => 25,
    }
}

Reverse Iterators

for i in (1..=50).rev() {
    print!("{} ", i);
}

Getting Input

The read_line() method of this trait can be used to read data, one line at a time, from a file or standard input stream. The stdin() function returns a handle to the standard input stream of the current process, to which the read_line function can be applied. This function tries to read all the characters present in the input buffer when it encounters an end-of-line character. The Writers in Rust are programs that can write data to a file or an output stream in bytes. The write() method is used for this purpose.

Command Line Arguments are passed to a program before executing it. They are like parameters passed to functions. CommandLine parameters can be used to pass values to the main() function. The std::env::args() returns the commandline arguments.

use std::io;
fn main() {
    let mut name = String::new();

    io::stdin().read_line(&mut name).unwrap();
    print!("Hello, {}", name);
}