Output using println macro in Rust - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the println! macro do in Rust?

It prints text to the console followed by a new line, allowing you to display output to the user.

beginner

How do you print a variable's value using println!?

Use curly braces {} as a placeholder inside the string, and pass the variable after the comma. Example: println!("Value: {}", x);

beginner

What happens if you use println! without any arguments?

It prints an empty line (just a new line) to the console.

intermediate

Can println! print multiple variables? How?

Yes, by using multiple placeholders {} and passing variables in order. Example: println!("{} and {}", a, b);

intermediate

What is the difference between print! and println! macros?

print! prints text without adding a new line at the end, while println! adds a new line after printing.

What will println!("Hello, {}!", "Rust"); output?

A Hello, Rust!

B Hello, {}!

C Hello, "Rust"!

D Error

The placeholder {} is replaced by the string "Rust", so it prints: Hello, Rust!

Which macro adds a new line after printing?

A print!

B println!

C write!

D format!

println! adds a new line after printing, unlike print!.

How do you print two variables a and b using println!?

A println!("{} {}", a, b);

B println!(a, b);

C println!("a and b");

D println!("{}", a + b);

Use placeholders for each variable and pass them in order.

What does println!(); print?

A Nothing

B A blank line

C Error

D The text 'println!'

It prints a blank line (just a new line).

Which of these is correct to print the value of variable x?

A println!("x");

B println!("{}", x);

C println!(x);

D println!("{x}");

Use {} as a placeholder and pass the variable after the comma.

Explain how to use the println! macro to print text and variables in Rust.

Think about how you combine text and values inside the macro.

What is the difference between print! and println! macros? When would you use each?

Consider how output appears on the console.