What are the various causes of getting null pointer exceptions?

In the context of Java programming a null pointer exception is found or occurs when a program tries to access a reference variable that is pointing towards a null element. This may occur due to various causes. It may occur when methods and operations are attempted in an object that is not started properly or when a reference has not been assigned for the specific object or element. For the instance:-

  String Str = null; Int length = str.length (); // causes a Null pointer Exception

If you want to get rid of this specific error then you should check for null references before performing actions on variables. This can be done by using conditional statements. For instance:-

    If (str != Null) { int length = str. Length(); safe operation if str is not null }

By using the above techniques one can easily get rid of this particular error.