Question

how is class a user defined data type​

Answer 1

Answer:

class is the find number of data members of different types.When an object is created , it contains all the members describe within the class .The class become such a data type that includes various primitive types

Answer 2

Answer:

Primitive data types are not sufficient.Java language uses some pre-defined data types such as int, float and char.

These data types are also known as composite data type, which provide some preliminary facilities in Java programming. Similarly, a user may create a data type and declare certain characteristics and behaviour within it. This can be done by using a class.

This is the main reason why a class is called as user defined data type.