Lifetimes in structs in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a struct with a lifetime parameter.

Rust

struct Book<[1]> {
    title: &[1] str,
}

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

A'b

B'static

C'a

D'lifetime

Attempts:

3 left

💡 Hint

Common Mistakes

Using a lifetime name without the apostrophe.

Using a different lifetime name in the struct and the reference.

The lifetime parameter 'a is used to tell Rust how long the reference inside the struct lives.

2fill in blank

medium

Complete the code to implement a method that returns the title reference.

Rust

impl<[1]> Book<[1]> {
    fn get_title(&self) -> &[1] str {
        self.title
    }
}

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

A'a

B'static

C'b

D'x

Attempts:

3 left

💡 Hint

Common Mistakes

Using different lifetime names in impl and method signature.

Omitting the lifetime parameter in impl.

The lifetime 'a must be consistent in the impl block and the method return type to ensure the reference is valid.

3fill in blank

hard

Fix the error by adding the correct lifetime to the struct field.

Rust

struct Person {
    name: &[1] str,
}

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

A'a

Bstatic

C'b

D'static

Attempts:

3 left

💡 Hint

Common Mistakes

Using a lifetime without declaring it in the struct.

Using a lifetime name without the apostrophe.

References in structs must have explicit lifetimes. Using 'static means the reference lives for the entire program.

4fill in blank

hard

Fill both blanks to create a struct with two references having the same lifetime.

Rust

struct Pair<[1]> {
    first: &[1] str,
    second: &[2] str,
}

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

A'a

B'b

D'c

Attempts:

3 left

💡 Hint

Common Mistakes

Using different lifetime names for the two references.

Not declaring the lifetime parameter in the struct.

Both references must share the same lifetime 'a to ensure they live as long as the struct.

5fill in blank

hard

Fill all three blanks to define a struct with a lifetime and implement a method returning a reference.

Rust

struct Message<[1]> {
    content: &[2] str,
}

impl<[3]> Message<[3]> {
    fn content(&self) -> &[3] str {
        self.content
    }
}

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

A'a

B'b

D'c

Attempts:

3 left

💡 Hint

Common Mistakes

Using different lifetime names in struct and impl.

Omitting the lifetime in the method return type.

The lifetime 'a must be declared and used consistently in the struct and impl blocks, and in the method signature.