This tutorial belongs to the Swift series

In Swift, semicolons are optional.

You can write statements on separate lines, and you don’t need to add a semicolon:

let list = ["a", "b", "c"]
var a = 2

You can add a semicolon, but it adds nothing meaningful in this case:

let list = ["a", "b", "c"];
var a = 2;

But if you want to write more than one statement on the same line, then you need to add a semicolon:

var a = 2; let b = 3