Object and Number class.txt

Terminal: echo $PATH	# This is where it looks for the applications that we want to open.

Class name always starts with a capital letter.

To understand code and see control flow, debug the code after putting breakpoint.
We can also change the values in debugger window to see what will happen at a particular value.

Input:
class Scanner to scan something i.e. Input something

command & click on class name to open class file. ex: cmd & click on 'Scanner'

javac -d . cmd.java
The -d switch specifies the destination where to put the generated class file.

OBJECT CLASS :
Object class is present in java.lang package.Every class in Java is directly or indirectly derived from the Object class.
If a Class does not extend any other class then it is direct child class of Object and if extends other class then it is
an indirectly derived. Therefore the Object class methods are available to all Java classes. Hence Object class acts as
a root of inheritance hierarchy in any Java Program.

There are methods in Object class:
toString(), hashCode(), equals(Object obj), getClass(), finalize(), clone(), etc.

NUMBER CLASS :
Most of the time, while working with numbers in java, we use primitive data types. But, Java also provides various
numeric wrapper sub classes under the abstract class Number present in java.lang package.There are mainly six subclasses
under Number class.These sub-classes define some useful methods which are used frequently while dealing with numbers.
Byte, Integer, Double, Short, Float, Long
NOTE : Primitive Wrapper Classes are Immutable in Java.