O'Reilly logo

Swift 3 ObjectOriented Programming - Second Edition by Gastón C. Hillar

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Building immutable classes

Mutability is very important in object-oriented programming. In fact, whenever we expose mutable properties, we create a class that will generate mutable instances. However, sometimes a mutable object can become a problem and in certain situations, we want to avoid objects changing their state. For example, when we work with concurrent code, an object that cannot change its state solves many concurrency problems and avoids potential bugs.

Tip

An immutable object is also known as a non-mutating object.

For example, we can create an immutable version of the previous MutableVector3D class to represent an immutable 3D vector. The new ImmutableVector3D class has three immutable instance properties declared with the let keyword ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required