28 Class Inheritance

Intermediate

Like most programming languages that support the class type, Cangjie supports class inheritance. If class B inherits class A, class A is the superclass and class B is the subclass. The subclass inherits all members of the superclass except private members and constructors

A class can only inherit one class. Abstract classes can always be inherited. Therefore, the open modifier is optional when an abstract class is defined. You can also use sealed to modify an abstract class, indicating that the abstract class can be inherited only in the current package. A non-abstract class can be inherited only if it is modified by open during definition.

Subclasses inherit all members of the superclass except private members and constructors.

Superclass constructor can be called using super().

inheritance.cj

open class Animal {
    public func sleep() {
        println("zzzzzzzzz")
    }
}

class Dog <: Animal {
    public func bark() {
        println("woof")
    }
}

main() {
    let lucy = Dog()
    lucy.sleep()
    lucy.bark()
}
// Output:
// zzzzzzzzz
// woof