Java Buzz Forum - What is NullPointerException in Java

NullPointerException in Java is a unchecked Exception defined in java.lang package and comes when a member of a an object either field or method is called on a object which is null. null is a keyword in Java which means nothing and calling method on Object whose value is null will result in NullPointerException. Since default value of Object is null, if you call any method or access any field on an Object which is not initialized will throw NullPointerException. Some programmer get confused with name as well, Since Java does not support pointers, How can you have NullPointerException in Java? Well java.lang.NullPointerException doesn't have anything to do with pointers, it just an Exception in Java. If you look at it more deeply, NullPointerException is an unchecked Exception and it's not mandatory to provide Exception handling code for it using try, catch and finally. In fact most of NullPointerException comes because of programming errors. See most common cause of NullPointerException to find out most common scenario where NullPointerException comes in Java. In this Java article we will not only see What is NullPointerException but also How to avoid NullPointerException and How to fix java.lang.NullPointerException in Java.


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