Result enum in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Result that holds a success value of 10.

Rust

let result: Result<i32, &str> = [1](10);

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

AErr

BSome

COk

DNone

Attempts:

3 left

💡 Hint

Common Mistakes

Using Err instead of Ok for success

Using Option variants like Some or None

The Ok variant of Result represents success and holds the value.

2fill in blank

medium

Complete the code to handle a Result and print the success value.

Rust

match result {
    [1](val) => println!("Success: {}", val),
    Err(e) => println!("Error: {}", e),
}

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

AOk

BNone

CSome

DErr

Attempts:

3 left

💡 Hint

Common Mistakes

Matching Err instead of Ok for success

Using Option variants in match

When matching a Result, the success case is Ok.

3fill in blank

hard

Fix the error in the code to unwrap the Result safely.

Rust

let value = result.[1](0);

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Aunwrap

Bunwrap_or

Cexpect

Dunwrap_err

Attempts:

3 left

💡 Hint

Common Mistakes

Using unwrap which panics on error

Using unwrap_err which unwraps the error variant

unwrap_or returns the success value or a default if it's an error.

4fill in blank

hard

Fill both blanks to create a Result and handle the error case.

Rust

let result: Result<i32, &str> = [1]("Failed");
match result {
    Ok(val) => println!("Value: {}", val),
    [2](e) => println!("Error: {}", e),
}

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

AErr

BOk

DSome

Attempts:

3 left

💡 Hint

Common Mistakes

Using Ok to create an error

Matching Ok instead of Err for errors

Err creates an error Result and matches the error case.

5fill in blank

hard

Fill all three blanks to map a Result's success value and handle errors.

Rust

let result: Result<i32, &str> = Ok(5);
let new_result = result.[1](|x| x [2] 2);
match new_result {
    Ok(val) => println!("Doubled: {}", val),
    [3](e) => println!("Error: {}", e),
}

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

Amap

B*

CErr

DOk

Attempts:

3 left

💡 Hint

Common Mistakes

Using map_err instead of map

Using + instead of * for multiplication

Matching Ok instead of Err for errors

map applies a function to the success value, * multiplies, and Err matches errors.