Rust Ownership Quiz

0 Passed

0% acceptance

45 in-depth questions covering Rust's ownership system, move semantics, copy types, resource cleanup through Drop trait, precise drop timing, and ownership transfer patterns — with 12 code examples to solidify understanding.

45 Questions

~90 minutes

Question 1

What are the three rules of ownership in Rust?

Each value has a single owner, ownership can be transferred, values are dropped when owner goes out of scope

Values can have multiple owners, borrowing is automatic, garbage collection handles cleanup

Ownership is shared by default, references are owning, manual memory management required

No ownership rules, everything is reference counted

Question 2

What happens when you assign a String to another variable?

The String is copied byte-for-byte

Ownership is moved, the first variable becomes invalid

Both variables share ownership

A reference is created automatically

Question 3

Which of these types implements Copy in Rust?

String

Vec<i32>

i32

Box<i32>

Question 4

What is the purpose of the Drop trait?

To define how values are cleaned up when they go out of scope

To prevent values from being dropped

To copy values instead of moving them

To share ownership between multiple variables

Question 5

When is a value's drop method called?

When the variable goes out of scope

Only when explicitly called

At program termination

When the value is moved

Question 6

What happens to ownership when you pass a value to a function?

Ownership is transferred to the function

The value is automatically borrowed

Ownership remains with the caller

The value is copied

Question 7

How can you avoid moving ownership when passing to a function?

Pass a reference using &

Use the move keyword

Pass by copy

Use Box<T>

Question 8

What will this code do?

rust

fn main() {
    let s = String::from("hello");
    take_ownership(s);
    println!("{}", s); // This line
}

fn take_ownership(s: String) {
    println!("{}", s);
}

Print 'hello' twice

Compilation error on the println! line

Print 'hello' once

Runtime panic

Question 9

What will this code do?

rust

fn main() {
    let s = String::from("hello");
    borrow_string(&s);
    println!("{}", s); // This line
}

fn borrow_string(s: &String) {
    println!("{}", s);
}

Print 'hello' twice

Compilation error

Print 'hello' once

Runtime panic

Question 10

When does Rust copy values instead of moving them?

For all types

Only for types that implement Copy

Only for primitive types

Never, Rust always moves

Question 11

What is the difference between Copy and Clone?

Copy is implicit, Clone is explicit

Copy is for primitives, Clone is for heap data

They are the same

Copy moves, Clone copies

Question 12

Can you implement Copy for a struct containing a String?

Yes, by deriving Copy

No, because String doesn't implement Copy

Yes, but you have to implement it manually

Only if the String is empty

Question 13

What happens when a value with a custom Drop implementation goes out of scope?

The drop method is called automatically

The value is leaked

The value is moved to static storage

Compilation error

Question 14

In what order are drop methods called for nested scopes?

Inner scopes first, then outer scopes

Outer scopes first, then inner scopes

Random order

No guaranteed order

Question 15

What will this code print?

rust

struct CustomDrop {
    id: i32,
}

impl Drop for CustomDrop {
    fn drop(&mut self) {
        println!("Dropping {}", self.id);
    }
}

fn main() {
    let a = CustomDrop { id: 1 };
    {
        let b = CustomDrop { id: 2 };
        let c = CustomDrop { id: 3 };
    }
    println!("End of main");
}

Dropping 1, Dropping 2, Dropping 3, End of main

Dropping 3, Dropping 2, Dropping 1, End of main

Dropping 1, Dropping 3, Dropping 2, End of main

End of main, Dropping 1, Dropping 2, Dropping 3

Question 16

How can you transfer ownership back from a function?

By returning the value

By using static variables

By modifying a global variable

Ownership cannot be transferred back

Question 17

What is ownership transfer useful for?

Preventing resource leaks

Enabling shared mutable state

Automatic reference counting

Dynamic dispatch

Question 18

When working with a database connection that needs to be closed when done, which ownership pattern is most appropriate?

Store the connection in a global variable

Use ownership transfer to ensure the connection is dropped when the owner goes out of scope

Use Rc<T> for shared ownership

Never close the connection

Question 19

What happens when you move a value into a Vec?

The value is copied

Ownership is transferred to the Vec

The value is borrowed

The Vec takes a reference

Question 20

How can you get ownership back from a Vec?

Use indexing like vec[0]

Use remove() or pop() methods

Use &vec[0]

Ownership cannot be retrieved from collections

Question 21

What will this code do?

rust

fn main() {
    let mut vec = Vec::new();
    let s = String::from("hello");
    vec.push(s);
    println!("{}", s); // This line
}

Print 'hello'

Compilation error

Runtime panic

Print nothing

Question 22

When implementing a cache that stores expensive-to-create objects, which ownership pattern should you use?

Store owned values and return them by value

Store references to external objects

Use Rc<T> for shared ownership

Store raw pointers

Question 23

What is the relationship between ownership and borrowing?

Borrowing temporarily suspends ownership rules

Borrowing creates shared ownership

Borrowing and ownership are unrelated

Borrowing replaces ownership

Question 24

When should you prefer moving over borrowing?

When you need to modify the value

When the caller no longer needs the value

When you need to return the value

All of the above

Question 25

What happens when you move a value that implements Drop?

Drop is called immediately

Drop is called when the new owner goes out of scope

Drop is never called

Drop is called twice

Question 26

In a web server handling requests, how should you manage database connections?

Create one global connection

Create connections per request with ownership transfer

Use static references

Never close connections

Question 27

What is the key difference between moving and copying?

Moving transfers ownership, copying duplicates data

Moving duplicates data, copying transfers ownership

They are the same

Moving is for primitives, copying for structs

Question 28

When implementing a file reader that should close the file automatically, which pattern should you use?

Manual close() calls

Ownership with Drop implementation

Global file handles

Never close files

Question 29

What will this code print?

rust

fn main() {
    let x = 5;
    let y = x;
    println!("x = {}, y = {}", x, y);
}

x = 5, y = 5

Compilation error

x = 5, y = 0

Runtime error

Question 30

What will this code do?

rust

fn main() {
    let s = String::from("hello");
    let t = s;
    println!("s = {}", s);
}

Print 's = hello'

Compilation error

Print 's = '

Runtime panic

Question 31

When should you implement Copy for your own types?

Always, for performance

When the type represents a simple value that should copy implicitly

Never, it's automatic

Only for primitives

Question 32

What happens if you try to derive Copy for a struct with a Vec field?

It works automatically

Compilation error because Vec doesn't implement Copy

It copies the Vec shallowly

It moves the Vec

Question 33

In a system managing temporary files, how should you handle file cleanup?

Manual deletion calls

Ownership transfer with Drop implementation for automatic cleanup

Store files in global state

Never delete temporary files

Question 34

What is the performance implication of moving large structs?

Moves are always expensive

Moves are cheap because they only copy pointers/metadata

Moves copy all data

Moves are impossible for large structs

Question 35

When implementing a parser that builds an AST, how should you handle node ownership?

Use Rc<T> for shared ownership

Transfer ownership of nodes to the AST structure

Store references to all nodes

Clone all nodes

Question 36

What will this code print?

rust

struct NoisyDrop {
    id: i32,
}

impl Drop for NoisyDrop {
    fn drop(&mut self) {
        println!("Dropping {}", self.id);
    }
}

fn main() {
    let a = NoisyDrop { id: 1 };
    let b = a;
    println!("End of main");
}

Dropping 1, End of main

End of main, Dropping 1

Dropping 1, Dropping 1, End of main

No output

Question 37

When should you avoid implementing Drop?

When the type has no resources to clean up

When you want manual control over cleanup

When the type implements Copy

All of the above

Question 38

In a multi-threaded application, how does ownership help prevent data races?

By allowing shared mutable access

By ensuring only one thread can own mutable data

By using garbage collection

Ownership doesn't help with concurrency

Question 39

What happens when you return a large struct from a function?

The entire struct is copied to the stack

Ownership is transferred efficiently

A reference is returned

The function panics

Question 40

When implementing a smart pointer like Box<T>, how should you handle the inner value's ownership?

Store it as a reference

Take ownership in the constructor and return it in Drop

Use Rc<T> internally

Never take ownership

Question 41

What is the relationship between ownership and the borrow checker?

The borrow checker enforces ownership rules

Ownership rules are separate from borrowing

The borrow checker replaces ownership

Ownership is checked at runtime

Question 42

In a library providing an API, how should you design function signatures for ownership?

Always take ownership

Always borrow

Use ownership when the function consumes the value, borrowing when it observes

Use Rc<T> for everything

Question 43

What will this code do?

rust

fn main() {
    let mut vec = Vec::new();
    for i in 0..3 {
        let s = format!("item {}", i);
        vec.push(s);
    }
    println!("Vec has {} items", vec.len());
    // vec goes out of scope here
}

Print 'Vec has 3 items' and leak memory

Compilation error

Print 'Vec has 3 items' and clean up properly

Runtime panic

Question 44

When implementing a configuration struct that holds database URLs, which ownership pattern is most appropriate?

Store String values for owned URLs

Store &str references

Use Rc<String> for sharing

Store raw pointers

Question 45

What is the most important benefit of Rust's ownership system?

Faster compilation

Memory safety without garbage collection

Object-oriented programming

Dynamic typing

Other Quiz Categories

JavaScript

47 quizzes

Basics

Variables & Data Types

Operators & Expressions

Python

29 quizzes

Introduction & Core Fundamentals

Data Types & Zero Values

Operators & Expressions

C++

26 quizzes

Basics

Variables & Data Types

Operators & Expression

Java

22 quizzes

Java Basics & JVM Fundamentals

Variables, Data Types & Type Casting

Operators & Expressions

Matlab

21 quizzes

Basics & Environment

Variables and Data Type

Arrays and Matric

TypeScript

19 quizzes

Introduction and Overview

Installation and Configuration

Basic Types and Type Annotations

SQL Database

15 quizzes

Foundations and Basics

Basic Query Selection

Filter, Sort, and Alias Essentials

PHP

15 quizzes

Syntax Building Blocks

Node Structure and Pointer Fundamentals

Singly Linked List

QUIZZES IN Rust

Cargo and Project Setup

40 comprehensive questions on Rust's package manager Cargo, covering project initialization, building, running, project structure, and dependency management — with 15 code examples demonstrating practical Cargo usage.

Variables and Mutability

40 comprehensive questions on Rust's variable system, covering let bindings, mut keyword, shadowing, type inference, and constants — with 12 code examples demonstrating practical variable usage patterns.

Data Types

45 comprehensive questions on Rust's type system, covering scalar types, compound types, type conversions, numeric operations, and string types — with 15 code examples demonstrating practical type usage patterns.

Control Flow

45 comprehensive questions on Rust's control flow constructs, covering if expressions, loops, and control flow keywords — with 15 code examples demonstrating practical control flow usage.

Functions

40 questions covering function parameters, return values, expressions, diverging functions, and function scope in Rust.

Ownership

Borrowing

45 in-depth questions covering Rust's borrowing system, immutable and mutable references, aliasing rules, reference scopes, and borrow checker validation — with 13 code examples to solidify understanding.

Lifetimes

40 in-depth questions covering Rust's lifetime system, lifetime annotations, elision rules, function signatures with lifetimes, struct references, and common lifetime errors — with 11 code examples to solidify understanding.

Strings

40 comprehensive questions on Rust's string types, covering String vs &str, UTF-8 behavior, slicing, mutating strings, and conversions — with 11 code examples demonstrating practical string handling patterns.

Collections

40 comprehensive questions on Rust's collection types, covering Vec, HashMap, VecDeque, iteration patterns, and capacity management — with 11 code examples demonstrating practical collection usage.

Slices

40 comprehensive questions on Rust's slice types, covering borrowed views, indexing, mutable slices, ranges, and slice methods — with 11 code examples demonstrating practical slice usage patterns.

Pattern Matching

40 comprehensive questions on Rust's pattern matching system, covering match expressions, destructuring, guards, wildcards, and enum matching — with 11 code examples demonstrating practical pattern matching techniques.

Enums

40 comprehensive questions on Rust's enum system, covering simple variants, data-carrying variants, enum matching, methods on enums, and Option/Result patterns — with 11 code examples demonstrating practical enum usage.

Struct

40 comprehensive questions on Rust's struct system, covering named fields, tuple structs, methods, associated functions, and field ownership — with 11 code examples demonstrating practical struct usage.

Modules

40 comprehensive questions on Rust's module system, covering module creation, visibility, imports, paths, and the use keyword — with 11 code examples demonstrating practical module organization patterns.

Traits

40 comprehensive questions on Rust's trait system, covering trait definitions, implementations, bounds, associated types, and trait objects — with 11 code examples demonstrating practical trait usage patterns.

Generic

40 comprehensive questions on Rust's generic programming system, covering generic functions, structs, enums, impl blocks, and monomorphization — with 11 code examples demonstrating practical generic usage patterns.

Iterators

Master Rust's powerful iterator system for efficient data processing and transformation

Closures

Master Rust's closure system for capturing environment variables and creating flexible function-like constructs

Error Handling

Master Rust's robust error handling system with Result, Option, and the ? operator for reliable code

File and I/O Operations

Master Rust's file system operations and I/O handling for robust data persistence and streaming

Smart Pointers

Master Rust's smart pointer types for automatic memory management and safe heap allocation

Concurrency

Master Rust's concurrency model with threads, channels, and synchronization primitives for safe parallel programming

Async Programming

Master asynchronous programming in Rust with futures, async/await, and concurrent execution patterns

Memory Management

Deep dive into Rust's ownership system, borrowing rules, and advanced memory management patterns for safe and efficient code

Macros

Master Rust's metaprogramming system with declarative and procedural macros for code generation and compile-time programming

Attributes

Master Rust's attribute system for conditional compilation, testing, documentation, and code generation

Testing

Master comprehensive testing strategies in Rust including unit tests, integration tests, documentation tests, and testing best practices

Crate Architecture

Master the design and organization of Rust crates including module systems, workspace management, dependency handling, and publishing strategies

Performance and Optimization

Master advanced performance techniques in Rust including profiling, benchmarking, memory optimization, and compiler optimizations

Rust Ownership Quiz

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18

Question 19

Question 20

Question 21

Question 22

Question 23

Question 24

Question 25

Question 26

Question 27

Question 28

Question 29

Question 30

Question 31

Question 32

Question 33

Question 34

Question 35

Question 36

Question 37

Question 38

Question 39

Question 40

Question 41

Question 42

Question 43

Question 44

Question 45

About This Rust Ownership Quiz

What You Will Practise

Other Quiz Categories

QUIZZES IN Rust

Cargo and Project Setup

Variables and Mutability

Data Types

Control Flow

Functions

Ownership

Borrowing

Lifetimes

Strings

Collections

Slices

Pattern Matching

Enums

Struct

Modules

Traits

Generic

Iterators

Closures

Error Handling

File and I/O Operations

Smart Pointers

Concurrency

Async Programming

Memory Management

Macros

Attributes

Testing

Crate Architecture

Performance and Optimization