Getting Started

Question 1

Which tool is recommended for installing and managing Rust versions?

Answer 1

rustup, a command-line installer and version manager for Rust toolchains.

Question 2

Why does the book tell you to install the stable toolchain?

Answer 2

Rust’s stability guarantees mean examples written for today’s stable compiler will keep compiling with future stable releases.

Question 3

Why might you need a C compiler after installing Rust?

Answer 3

Rust links final binaries and many crates include C code; a C tool-chain provides the linker.

Question 4

How do you confirm Rust is installed correctly?

Answer 4

Run rustc –version; you should see rustc x.y.z (commit-hash yyyy-mm-dd).

Question 5

Single command to keep Rust up to date?

Answer 5

rustup update downloads and installs the newest stable toolchain.

Question 6

If you don’t want to use rustup, where should you look?

Answer 6

The Other Rust Installation Methods page linked near the top of the guide.

Question 7

What shorthand nickname do Rust developers use for themselves?

Answer 7

Rustaceans—you’ll see the term on the community sites.

Question 8

What is the mandatory entry-point function that every executable Rust program must define?

Answer 8

main (it’s the first code that runs).

Question 9

Where are a function’s body and its statements placed in Rust?

Answer 9

Inside { } curly braces following the function header.

Question 10

What file-name extension must every Rust source file use?

Answer 10

.rs

Question 11

When a filename contains multiple words, what delimiter is conventional in Rust?

Answer 11

An underscore, e.g., hello_world.rs (not helloworld.rs).

Question 12

Which command compiles a single Rust source file?

Answer 12

rustc <filename>.rs (e.g., rustc main.rs).</filename>

Question 13

Which Rust construct prints text to the terminal in the “Hello, world!” example?

Answer 13

The macro println!(“Hello, world!”);.

Question 14

How can you visually distinguish a macro call from a function call in Rust?

Answer 14

A macro ends with an exclamation mark (!), e.g., println!.

Question 15

What punctuation ends most Rust statements and expressions?

Answer 15

A semicolon (;).

Question 16

Why is Rust described as an “ahead-of-time compiled” language?

Answer 16

You compile to a standalone binary that can run on a machine without Rust installed.

Question 17

Compared with dynamic languages like Python or JavaScript, what extra step does Rust require before execution?

Answer 17

An explicit compilation step separate from running the program.

Question 18

What automatic formatting tool ships with the standard Rust distribution?

Answer 18

rustfmt

Question 19

Which language-server/IDE helper is the Rust team focusing on?

Answer 19

rust-analyzer

Question 20

Why might you separate compiling and running when your Rust project grows?

Answer 20

To manage many build options and dependencies more easily (leading to the introduction of Cargo).

Question 21

What is Cargo?

Answer 21

Cargo is Rust’s build system and package manager; it builds your code, fetches dependencies (called crates), and builds those crates too.

Question 22

How do you verify that Cargo is installed?

Answer 22

Run cargo –version in your terminal; a version string indicates success.

Question 23

Which command creates a brand-new Cargo project?

Answer 23

cargo new project_name (e.g., cargo new hello_cargo).

Question 24

What three items does cargo new generate?

Answer 24

A Cargo.toml file, a src directory containing main.rs, and (by default) an initialized Git repository with .gitignore.

Question 25

Where does Cargo expect your source code to live?

Answer 25

Inside the src directory of the project; the top-level folder is reserved for docs, configs, etc.

Question 26

What is the purpose of the [dependencies] section in Cargo.toml?

Answer 26

It lists external crates your project relies on; Cargo downloads and manages them automatically.

Question 27

Which command compiles your project in debug mode?

Answer 27

cargo build — it outputs the binary to target/debug/.

Question 28

How do you compile and run in one step?

Answer 28

Use cargo run; it builds (if needed) and then executes the binary.

Question 29

Which command quickly verifies compilation without creating a binary?

Answer 29

cargo check, ideal for rapid syntax/borrow checking while you code.

Question 30

What file does Cargo create on first build to pin exact dependency versions?

Answer 30

Cargo.lock; Cargo maintains it automatically.

Question 31

How can you convert a manual Rust project into a Cargo project?

Answer 31

Move code into src/ and run cargo init to generate a suitable Cargo.toml.

Question 32

Which command produces an optimized release binary? Where is it placed?

Answer 32

cargo build --release; the binary lands in target/release/.

Question 33

Why are there separate debug and release profiles?

Answer 33

Debug builds compile quickly with debug info; release builds take longer but run faster thanks to optimizations.

Question 34

What advantage does Cargo give across different operating systems?

Answer 34

The same Cargo commands work on Linux, macOS, and Windows, so you don’t memorize platform-specific toolchains.

Question 35

How can you change the VCS behavior when creating a project?

Answer 35

Add --vcs (e.g., cargo new myapp --vcs=git or --vcs=none).

Question 36

In Rust terminology, what is a crate?

Answer 36

A package of Rust code that can be compiled or depended upon; your package may contain one (or more) crates.

Question 37

Why is using Cargo preferable once a program spans multiple files or uses dependencies?

Answer 37

Cargo orchestrates compilation order and dependency fetching automatically, saving manual rustc invocations.

Question 38

List the 4 most-common day-to-day Cargo commands.

Answer 38

cargo new, cargo build, cargo run, cargo check — they cover project creation, compilation, execution, and rapid checking.