Interview questions(like diff bettween two) in java

S.No	Abstract	Interface
1	Single inheritance	Multiple inheritance
2	Non abstarct mtd also	Only abstarct mtds
3	Non-static and non-final variables also.	Variables must be static and final(implicitly)
4	Non public members also	Only public mbrs
5	Using extends keyword	Using implements keyword
6	It can invoke if main exists	Pure abtract
7	Faster	Flexible

S.No	Constructor	Method
1	Member function of class.	Ordinary member function.
2	Same as class name.	Own name
3	Invoke using new operator	Invoke using dot operator.
4	No-return type.	It have.

S.No	ArrayList	Vector
1	Its a growable array.	Synchronized ArrayList.
2	Not thread safe	Thread safe.

S.No	HashMap	HashTable
1	Un ordered and un sorted map. Not thread safe.	Synchronized HashMap. Thread safe.
2	It allows one null key and multiple null values	It wont allow no null key/values.

S.No	AWT	SWING
1	Heay Weight Component.	Light Weight Component.
2	Component use native methods.	Use the methods that r written in java.
3	It have their own viewport which sends the output to the screen.	It does not write itself to the screen, but redirect it to the component it builds
4	Platform dependent.	Platform independent.
5	Old	Its advanced AWT. 1.Its provide additional components like Jtable,JTabbedPane 2. can add icons and tooltips. 3. built on double buffering.
6	Support Event Delegation Model	MVC architecture,
7	Static Look and feel.	Dynamic Look and feel.

S.No	InvokeAndWait	InvokeLater
1	Synchronous.	Asynchronous.
2	It blocks until runnable task is complete.	It posts an actionevent to the event queue and returns immediately.

S.No	Font	FontMetrics
1	It is used to render text data onto the screen	It provides access to attributes of Font Objects, thing such as charwidth, charheight ,ascents and descent of a font Object.

S.No	String	StringBuffer
1	Immutable(cant change content )	Mutable(can change content using append mtd)
2	Not thread safe.	Thread safe.

S.No	Jlist	JcomboBox
1	Its dont have Editor Component.	It have Editor Component.
2	It allows single,single interval and multiple interval selection.	It allow only single selection.

S.No	Encapsulation	Abstraction
1	It is the mechanism that binds together the code and the data it manipulates and keeps both safe from outside information and misuse.	It denotes the essential characterstics of an object which differentiate from other object.
2	Hiding irrevelents details of an object.	Showing essential things of an object.