4.1 Code structure

4.1.1Semicolon separator¶

Rust code is organized in statements separated by semicolons. In practice, each statement is written on one line and terminated with a semicolon, like in the following example in which two statements are written:

let a = 10;
println!("{a}");

10

Since the semicolon is a separator, we may also write those two statements on a single line:

let a = 10; println!("{a}");

10

A statement may be divided into multiple lines, for instance to avoid excessive length:

assert_eq!(format!("a {} b {} c {} d {} e {} f {}", 1, 2, 3, 4, 5, 6),
  format!("{} 1 {} 2 {} 3 {} 4 {} 5 {} 6", 'a', 'b', 'c', 'd', 'e', 'f'));

4.1.2Curly brackets¶

Statements can be grouped using curly brackets:

{
  let a = 10;
  println!("{a}");
}
{
  let b = 15;
  println!("{b}");
}

10

15

Curly brackets are also used to delimit the bodies of functions:

fn foo() {
  println!("Hello!");
}

foo();

Hello!

Or the blocks of control flows:

for i in 0..10 {
  print!("{i} ");
}
println!("")

0 1 2 3 4 5 6 7 8 9 

4.1.3Naming conventions¶

In Rust, naming conventions (see Naming conventions) are as shown in Table 1.