• Rust uses a lot of special symbols like { and )

  • Many of these symbols come in pairs

  • These pairs of symbols need to nest inside each other

  • It’s good practice to follow layout rules to make your code easier to read

  • The rustfmt tool can help you get the layout right

  • You can use // or /* */ to add comments to your code

  • An expression is evaluated to a value of a specific type

  • Most of our Rust code is writing expressions

  • You can draw out expressions as trees, and then evaluate from the bottom up

  • Variables are a convenient way to capture expression results and give them useful names

  • Some expressions cause effects to happen

  • All expressions produce a result

  • But when an expression has nothing useful to produce, it produces (), aka unit

  • The body of a function is a block

  • Blocks can contain multiple statements, and end with an optional expression

  • The semicolon throws away the result of an expression

  • If you end your block with an expression without a semicolon, it will produce that value, otherwise it produces unit

Get hands-on with 1200+ tech skills courses.