Primitives vs. Objects

Properties	Primitive data types	Objects
Origin	Pre-defined data types	User-defined data types
Stored structure	Stored in a stack	Reference variable is stored in stack and the original object is stored in heap
When copied	Two different variables is created along with different assignment(only values are same)	Two reference variable is created but both are pointing to the same object on the heap
When changes are made in the copied variable	Change does not reflect in the original ones.	Changes reflected in the original ones.
Default value	Primitive datatypes do not have null as default value	The default value for the reference variable is null
Example	byte, short, int, long, float, double, char, boolean	array, string class, interface etc.

What Is an Exception?

Definition: An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program’s instructions.

• The call stack:

• Searching the call stack for the exception handler:

The Catch or Specify Requirement

Valid Java programming language code must honor the Catch or Specify Requirement. This means that code that might throw certain exceptions must be enclosed by either of the following:

A try statement that catches the exception. The try must provide a handler for the exception, as described in Catching and Handling Exceptions. A method that specifies that it can throw the exception. The method must provide a throws clause that lists the exception, as described in Specifying the Exceptions Thrown by a Method. Code that fails to honor the Catch or Specify Requirement will not compile.