{"id":77198,"date":"2020-03-16T10:15:05","date_gmt":"2020-03-16T04:45:05","guid":{"rendered":"https:\/\/techvidvan.com\/tutorials\/?p=77198"},"modified":"2020-03-16T10:15:05","modified_gmt":"2020-03-16T04:45:05","slug":"java-wrapper-class","status":"publish","type":"post","link":"https:\/\/techvidvan.com\/tutorials\/java-wrapper-class\/","title":{"rendered":"Wrapper Class in Java – Learn Autoboxing & Unboxing with Coding Examples"},"content":{"rendered":"

Java is not a purely object-oriented programming language, the reason being it works on primitive data types. These eight primitive data types int, short, byte, long, float, double, char and, boolean are not objects.<\/p>\n

We use wrapper classes to use these data types in the form of objects. Wrapper class in Java makes the Java code fully object-oriented. For example, converting an int to Integer. Here int is a data type and Integer is the wrapper class of int.<\/p>\n

We will discuss the concept of wrapper classes in Java with the examples. There are several reasons why we prefer a wrapper class instead of a primitive type; we will discuss them as well in this article. We will also discuss Autoboxing and Unboxing in Java.<\/p>\n

Let’s take a quick revision on Data Types in Java<\/a> to clear your basics with Techvidvan.\u00a0<\/strong><\/em><\/p>\n

Wrapper class in Java<\/h3>\n

Sometimes in the process of development, we come across situations where there is a need for objects instead of primitive data types. To achieve this, Java provides a concept of Wrapper classes.<\/p>\n

A Wrapper class<\/strong> in Java is the type of class that provides a mechanism to convert the primitive data types into the objects and vice-versa.<\/p>\n

When a wrapper class is created, there is a creation of a new field in which we store the primitive data types. The object of the wrapper class wraps or holds its respective primitive data type.<\/p>\n

The process of converting primitive data types into an object is called boxing. While using a wrapper class, you just have to pass the value of the primitive data type to the constructor of the Wrapper class.<\/p>\n

All the wrapper classes Byte, Short, Integer, Long, Double and, Float, are subclasses of the abstract class Number.<\/strong> While Character and Boolean wrapper classes are the subclasses of class Object.<\/strong><\/p>\n

The diagram below shows the hierarchy of the wrapper classes.<\/p>\n

\"Java<\/a><\/p>\n\n\n\n\n\n\n\n\n\n\n\n
Primitive Data Type<\/b><\/td>\nWrapper Class<\/b><\/td>\nConstructor Argument<\/b><\/td>\n<\/tr>\n
boolean<\/span><\/td>\nBoolean<\/b><\/td>\nboolean or String<\/span><\/td>\n<\/tr>\n
byte<\/span><\/td>\nByte<\/b><\/td>\nbyte or String<\/span><\/td>\n<\/tr>\n
char<\/span><\/td>\nCharacter<\/b><\/td>\nchar<\/span><\/td>\n<\/tr>\n
int<\/span><\/td>\nInteger<\/b><\/td>\nint or String<\/span><\/td>\n<\/tr>\n
float<\/span><\/td>\nFloat<\/b><\/td>\nfloat, double or String<\/span><\/td>\n<\/tr>\n
double<\/span><\/td>\nDouble<\/b><\/td>\ndouble or String<\/span><\/td>\n<\/tr>\n
long<\/span><\/td>\nLong<\/b><\/td>\nlong or String<\/span><\/td>\n<\/tr>\n
short<\/span><\/td>\nShort<\/b><\/td>\nshort or String<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Need for Wrapper class in Java<\/h3>\n