http://www.allinterview.com Top Core Java Interview Questions en-us http://www.allinterview.com/showanswers/23154.html System: System refers to current java program. out: out refers to output device. by default it is monitor. println: to print the specific string onto output device in next line http://www.allinterview.com/showanswers/32553.html There are three types of oops in java. 1.Encapsulation:Encapsulation is mechanism,that binds together data and code its manipulates. Ex:suppose we are writing one bean.we declaring two private variables.we are providing setters and getters method http://www.allinterview.com/showanswers/23767.html See the diffrence is that core java is the fundamental for java that will be used in any java technology without this no one can jump on any advance java technology. Where as advance java is specialisation in some domain , as someone in networki http://www.allinterview.com/showanswers/11031.html 1)We define an Interface in the Java application with a set of abstract methods without any implementation. Which means all the methods of an interface are by default abstract methods and public methods. 2)Once an Interface is defined in the http://www.allinterview.com/showanswers/1065.html Access specifiers :: The access specifier determines how accessible the field is to code in other classes. Access ranges from totally accessible to totally inaccessible. You can optionally declare a field with an access specifier keyword: p http://www.allinterview.com/showanswers/20264.html 1. Arraylist is not synchronized while vector is. 2. Arraylist has no default size while vector has a default size of 10. http://www.allinterview.com/showanswers/16522.html Java absolutly support multiple inheritence in terms of Interface.We can extend one class only to avoid ambiguity problem.In interface we have to define the functions.So we don't get any ambiguity.In c++ it is big problem with multiple i http://www.allinterview.com/showanswers/4966.html A class can be marked by the "private" access specifier only if its a nested member of another class. Top level classes cannot be marked as "private". Hence you can have private classes in a java file but they must be nested http://www.allinterview.com/showanswers/20263.html Hashmap work as like as Hashtable but hashtable is synchronised hash map was not sychronized hashtable does not allow null values hashmap allows null values http://www.allinterview.com/showanswers/4105.html A java.util.ArrayList has the following characteristics over an array: 1. Provides a resizable array implementation 2. Implements the java.util.List interface 3. Has a tuning parameter called initialCapacity which specifies the number of eleme http://www.allinterview.com/showanswers/59459.html Encapsulation Abstraction polymorphisms inheritance/delegation http://www.allinterview.com/showanswers/4082.html JDK or the Java Development Kit is a set of a Java compiler, a Java interpreter, developer tools, Java API libraries, documentation which can be used by Java developers to develop Java-based applications. JRE or the Java Runtime Environment is http://www.allinterview.com/showanswers/2074.html The Reader/Writer class is character-oriented and the InputStream/OutputStream class is byte-oriented. http://www.allinterview.com/showanswers/4100.html polymorphism -an entity existing in different forms at the same time. Polymorphism is of two types. Static polymorphism and dynamic polymorphism. Run time polymorphism refers to dynamic polymorphism wherein an entity changes it's form de http://www.allinterview.com/showanswers/32551.html Class is a template(type) or blue print its state how objects should be and behave. eg consider a construction plan which is a class with this description mentioned in a plan we can constructs 'n' number of buildings of same type. th