Differentiate between Primitives and Objects

• Everything in Java is an "Object", as every class by default inherits from class

"Object", except a few primitive data types, which are there for efficiency reasons.

• Primitive Data Types

Primitive Data types of java

boolean, byte                1 byte

char, short                   2 bytes

int, float                      4 bytes

long, double                 8 bytes

• Primitive data types are normally used for local variables, parameters and instance variables (properties of an object)
• Primitive datatype are located on stack and we can only access their value whereas objects are located on heap and we have a reference to these objects
• Additionally primitive data types are always passed by value while objects are always passed by reference in java. There is no C++ like methods

- void someMethod (int &a, int & b) // not available in java