Kotlin Android Training – Beginner Android App Development [FREE]

Even though Kotlin is a full-fledged functional programming language, it preserves most of the object-oriented nature of Java as an alternative programming style, which is very handy when converting existing Java code. Kotlin has classes with constructors, along with nested, inner, and anonymous inner classes, and it has interfaces like Java 8. Kotlin does not have a new keyword. To create a class instance, call the constructor just like a regular function. We saw that in the screenshot above.

Kotlin has single inheritance from a named superclass, and all Kotlin classes have a default superclass Any, which is not the same as the Java base class java.lang.Object. Any contains only three predefined member functions: equals(), hashCode(), and toString().