Can a class have another class inside it?

In java you cannot create a method outside of a class . All methods must be encapsulated within a class. Therefore the main method as an entry point to the program must be within a class. When you run this program the main method will be run once and will execute the code inside it.

A class can be declared within the scope of another class . Such a class is called a “nested class.” Nested classes are considered to be within the scope of the enclosing class and are available for use within that scope.

To create an object of Main , specify the class name, followed by the object name, and use the keyword new :

To instantiate an inner class, you must first instantiate the outer class. Then, create the inner object within the outer object with this syntax: OuterClass outerObject = new OuterClass(); OuterClass. InnerClass innerObject = outerObject .