Formatting output in Rust - Cheat Sheet & Quick Revision

Recall & Review

beginner

What macro is commonly used in Rust to print formatted output to the console?

The println! macro is used to print formatted output to the console in Rust.

beginner

How do you insert a variable's value inside a string using Rust's formatting syntax?

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

intermediate

What does the format specifier {:.2} do in Rust's formatting?

It formats a floating-point number to show exactly 2 digits after the decimal point.

intermediate

How can you align text to the right with a width of 10 characters in Rust formatting?

Use {:>10} inside the format string. This pads the text on the left to make the total width 10 characters.

beginner

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

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

Which macro in Rust adds a newline after printing?

A eprintln!

B print!

C format!

D println!

println! prints text and adds a newline. print! does not add a newline.

How do you format a floating-point number to 3 decimal places in Rust?

A {:.3}

B {:3}

C {.3}

D {3}

The syntax {:.3} formats a float to 3 decimal places.

What does {:>8} do in a format string?

A Left-align text with width 8

B Right-align text with width 8

C Center-align text with width 8

D Truncate text to 8 characters

{:>8} right-aligns the text and pads with spaces to width 8.

Which macro returns a formatted string without printing it?

A format!

B print!

C eprint!

D println!

format! creates a formatted string but does not print it.

How do you include a literal curly brace character in a Rust format string?

A Use single braces {}

B Escape with backslash \{

C Use double braces {{ or }}

D Use parentheses ()

Double braces {{ or }} print a literal curly brace.

Explain how to format a floating-point number to 2 decimal places and align it right with width 10 in Rust.

Think about combining precision and alignment inside the curly braces.

Describe the difference between print!, println!, and format! macros in Rust.

Consider what each macro does with the output.