Easily understand the Swift programming language

Swift is a modern, powerful and easy-to-learn programming language developed by Apple. It combines the advantages of C and Objective-C and introduces many new features to make writing iOS, macOS, watchOS and tvOS applications easier and more efficient. This article will introduce some key concepts and syntax of Swift in detail, and help you understand better through sample code.

1. Variables and constants

In Swift, you can vardeclare a mutable variable using the keyword and letan immutable constant using the keyword. Variables and constants must be declared before they can be used, and the type must be specified or inferred through assignment. Here's a simple example:

var myVariable = 10
let myConstant = 20
myVariable = 30

In the above code, myVariableis a mutable variable with an initial value of 10. myConstantis an immutable constant with an initial value of 20. You can change the value of a mutable variable through assignment, but you cannot change the value of a constant.

2. type of data

Swift has a rich set of data types, including integers, floating point numbers, Boolean values, strings, and sets. The following is