Swift For Dummies

Chapter 10

Expressing Yourself

In This Chapter

Understanding optional types

Choosing types of expressions

Using lazy loading for properties with closures

Expressions in Swift are very similar to expressions in other programming languages, but there are some differences (of course). Some of these differences arise from Swift-specific features, whereas some simply reflect the requirements of a 21st-century language designed to be developed on extraordinarily powerful computers.

Swift is designed to be easily modified by Apple as circumstances change. In addition, you can define new operators for your own apps. A great deal of flexibility is built in, but in the future there may be added expression syntax both from Apple and from other Swift developers.

Expressions involve not just operators and variables but also the Cocoa and Cocoa Touch frameworks. The best reference for all of these is developer.apple.com. Even without registering, you can search the site for information about the developer tools and languages, making this the first place to turn if you have questions.

Surveying the Types of Swift Expressions

Expressions involve targets (which themselves can be expressions, ...