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Similar to the Integer wrapper class for the int datatype, each of the eight primitive types has a wrapper class defined
for it (in the java.lang package) all of which are imported by default in Java programs. Table given below lists the
wrapper classes for the corresponding datatype.
Primitive Datatype Wrapper Class
boolean Boolean
byte Byte
char Char
int Int
float Float
double Double
long Long
short Short
3.12 cLaSS dESIgn
We are now ready to create a class in Java. A class in Java begins with the keyword class followed by the name of the class.
The body of the class is enclosed within curly braces. The body contains the definitions of the data and method members
of the class. The data members are defined by specifying their type. The method members of the class are defined just
like the user defined methods we saw earlier. The method members have access to all the data members of the class and
can use them in their body. The data members of a class are like global variables – they can be accessed by all the method
members of the class.
How to code the class Book in Java is shown below:
public class Book
{
String title;
String author;
String publisher;
String genre;
double price;
void display()
{
System.out.printin (“Title “+title);
System.out.printin (“author “+author);
System.out.printin (“publisher “+publisher);
System.out.printin (“genre “+genre);
System.out.printin (“price “+price);
}
}
Fundamentals of Java Programming 251

