The final difference between classes and structs is the way they deal with constants. If you have a constant struct with a variable property, that property can’t be changed because the struct itself is constant.
However, if you have a constant class with a variable property, that property can be changed. Because of this, classes don’t need the mutating
keyword with methods that change properties; that’s only needed with structs.
This difference means you can change any variable property on a class even when the class is created as a constant – this is perfectly valid code:
class Singer {
var name = "Taylor Swift"
}
let taylor = Singer()
taylor.name = "Ed Sheeran"
print(taylor.name)
If you want to stop that from happening you need to make the property constant:
class Singer {
let name = "Taylor Swift"
}
SPONSORED Would you describe yourself as knowledgeable, but struggling when you have to come up with your own code? Fernando Olivares has a new book containing iOS rules you can immediately apply to your coding habits to see dramatic improvements, while also teaching applied programming fundamentals seen in refactored code from published apps.
Sponsor Hacking with Swift and reach the world's largest Swift community!
Link copied to your pasteboard.