What is null pointer exception in Java and how to fix it?

A null pointer exception is thrown Whenever you try to

• Call the instance method of a null object.
• Access, modify, print, a null value.
• Trying to access (print/use in statements) the length of the null value.
• Throw a null value.
• Access an element of an array without initializing it.

Then, a Null Pointer Exception will be thrown.