Handling input values in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read a line of input from the user.

Rust

use std::io;

fn main() {
    let mut input = String::new();
    io::stdin().[1](&mut input).expect("Failed to read line");
    println!("You typed: {}", input.trim());
}

Drag options to blanks, or click blank then click option'

Aread_exact

Bread_to_string

Cread_line

Dread

Attempts:

3 left

💡 Hint

Common Mistakes

Using read_to_string which reads until EOF, not just one line.

Using read_exact which requires a fixed-size buffer.

The read_line method reads a line from standard input into the provided string buffer.

2fill in blank

medium

Complete the code to convert the input string to an integer.

Rust

use std::io;

fn main() {
    let mut input = String::new();
    io::stdin().read_line(&mut input).expect("Failed to read line");
    let num: i32 = input.trim().[1]().expect("Please type a number!");
    println!("You typed the number: {}", num);
}

Drag options to blanks, or click blank then click option'

Aparse

Bto_string

Cparse_int

Dto_int

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like to_int or parse_int.

Forgetting to trim the input before parsing.

The parse method converts a string slice into a number type, here i32.

3fill in blank

hard

Fix the error in the code to correctly handle input and parse it as a floating-point number.

Rust

use std::io;

fn main() {
    let mut input = String::new();
    io::stdin().read_line(&mut input).expect("Failed to read line");
    let num: f64 = input.[1]().expect("Please type a number!");
    println!("You typed the number: {}", num);
}

Drag options to blanks, or click blank then click option'

Aparse

Btrim

Cto_string

Dparse_float

Attempts:

3 left

💡 Hint

Common Mistakes

Calling parse directly on the input string with newline characters.

Using non-existent methods like parse_float.

You must call trim() before parse() to remove whitespace and newline characters.

4fill in blank

hard

Fill both blanks to read input, trim it, and parse it as an unsigned integer.

Rust

use std::io;

fn main() {
    let mut input = String::new();
    io::stdin().[1](&mut input).expect("Failed to read line");
    let num: u32 = input.[2]().parse().expect("Please type a number!");
    println!("Number: {}", num);
}

Drag options to blanks, or click blank then click option'

Aread_line

Bread_to_string

Ctrim

Dto_string

Attempts:

3 left

💡 Hint

Common Mistakes

Using read_to_string which reads until EOF.

Not trimming input before parsing.

First, use read_line to get input. Then trim removes whitespace before parsing.

5fill in blank

hard

Fill all three blanks to read input, trim it, parse it as i64, and handle possible errors.

Rust

use std::io;

fn main() {
    let mut input = String::new();
    io::stdin().[1](&mut input).expect("Failed to read line");
    let trimmed = input.[2]();
    let num: i64 = match trimmed.parse() {
        Ok(n) => n,
        Err(_) => {
            println!("Invalid number");
            return;
        }
    };
    println!("You typed: {}", num);
}

Drag options to blanks, or click blank then click option'

Aread_line

Btrim

Cparse

Dto_string

Attempts:

3 left

💡 Hint

Common Mistakes

Not handling parse errors with match.

Using to_string unnecessarily.

Use read_line to get input, trim to clean it, and parse to convert to a number with error handling.