Simple example program for wrapper class in java

Java ArrayList. Popular Examples Check prime number. Print the Fibonacci series. Print Pyramids and Patterns. Multiply two matrices. Find the standard deviation. Reference Materials String. Start Learning Java. Explore Java Examples. Related Topics Java autoboxing and unboxing. Java Data Types Primitive.

Java ArrayList remove. Java String valueOf. Java Wrapper Class In this tutorial, we will learn about the Java Wrapper class with the help of examples.

Each of the 8 primitive types has corresponding wrapper classes. An object of Double is created. When we create an object to a wrapper class, it contains a field and in this field, we can store primitive data types.

In other words, we can wrap a primitive value into a wrapper class object. Need of Wrapper Classes They convert primitive data types into objects. Objects are needed if we wish to modify the arguments passed into a method because primitive types are passed by value. The classes in java. Data structures in the Collection framework, such as ArrayList and Vector , store only objects reference types and not primitive types.

An object is needed to support synchronization in multithreading. Skip to content. Change Language. Related Articles. Basics of Java. Operators in Java.

Packages in Java. Flow Control in Java. Loops in Java. In the following example, we convert an Integer to a String , and use the length method of the String class to output the length of the "string":. We just launched W3Schools videos.

Get certified by completing a course today! If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail:. Report Error. Your message has been sent to W3Schools. W3Schools is optimized for learning and training.