Primitive vs reference types Java

The eight primitive data types byte, short, int, long, float, double, char and boolean are not objects, Wrapper classes are used for converting primitive data types into objects, like int to Integer etc. Lets take a simple example to understand why we need wrapper class in java.

The difference between primitive and non-primitive data types are as follows: Primitive types are predefined in Java. Non-primitive types are created by the programmer and is not defined by Java . Non Primitive types can be used to call methods to perform certain operations, while primitive types cannot.

Wrapper Classes A wrapper class is an object that encapsulates a primitive type . Each primitive type has a corresponding wrapper: byte, short, int, long, float, double, boolean, char.18 Mar 2019

The primary advantage of Wrapper Classes is that we need Wrapper objects to function with collections which is only possible with the help of Wrapper classes . As the wrapper classes have objects we can store null as a value. We could not store null in variables of primitive datatype.

Instead of create variables using new, Java can use primitive types to create automatic variables that are not references . The variables hold the value, and it’s place on the stack so its much more efficient. Java determines the size of each primitive type.

Wrapper Class will convert primitive data types into objects . The objects are necessary if we wish to modify the arguments passed into the method (because primitive types are passed by value). The classes in java. util package handles only objects and hence wrapper classes help in this case also.