class Comparison Table

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class comparison table

Subject return is a synonym of access from specify you use create you use communicate with implement be part of model see also contain import automatically into permit put into is a kind of enable receive have access to send define in be a subclass of is part of has definition refer to by define be the opposite of wait on require to be is a subtopic of correspond to have example of creation access refer to hide convert into is an instance of have methods convert be a member of notify have purpose omit relate to has part create by throw when provide share have be not

abstract class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A class that can only be subclassed - it cannot be instantiated or the compiler will display an error message and refuse to compile the program
if a class is not declared public
then it is accessible only to members of the same package
generic behaviour concrete class have any abstract methods final Classes any public class in other packages 1 named package rather than the default package to hold features that will be inherited by two or more subclasses some or all of the implementation of its methods specifying the abstract keyword on the first line when you declare the class 0 or more method declarations for all methods needed to implement its programming interface to its subclasses instances fully defined

ancestor ascendant class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A class A is an ancestor of class B if it is farther up in the class hierarchy than class B and class B is descended from it
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Inheritance any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

Applet class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface applet package data associated with each object
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Applets any public class in other packages class 1 named package rather than the default package implementation for all its instance methods unless the class is abstract stopping procedure in the Stop() method

class defined within a method an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Classes fields within the method only if the fields are defined as final 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

class in a package an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object a directory with the same name as the package class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Packages any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

class that implements an interface an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Interfaces any public class in other packages 1 named package rather than the default package other classes that implement the same interface in any other way implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

class that imports a package an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class methods and variables in the imported package that are not declared public
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Packages any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

collection class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Collections any public class in other packages 1 named package rather than the default package working with collections of objects implementation for all its instance methods unless the class is abstract iterator method for doing something with every member of the collection

concrete class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A class that can have instances
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type abstract class the unit of data abstraction in an object-oriented program Classes any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

core class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A public class (or interface) that is a standard member of the Java Platform
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program How Java Works any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

descendent an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A class that inherits from another
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Inheritance any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

Exception class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface exception data associated with each object
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Exception Handling any public class in other packages class 1 named package rather than the default package implementation for all its instance methods unless the class is abstract specification

FileInputStream to read bytes from a file more than one interface data associated with each object reading 1 byte at a time
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Input and Output
FileInputStream stream = new FileInputStrem(inputFileNameOrPath);
any public class in other packages stream 1 named package rather than the default package implementation for all its instance methods unless the class is abstract specification

final class the keyword final before the keyword class in the class declaration an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A class that cannot have subclasses
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type abstract Classes any public class in other packages 1 named package rather than the default package to increase system security by preventing system subversion implementation for all its instance methods unless the class is abstract a subclass or the compiler will display an error message

JApplet an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class to use Swing components Applet class Java 2
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Example Classes any public class in other packages class 1 named package rather than the default package implementation for all its instance methods unless the class is abstract specification

main class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class The class which contains the main method and whose name is specified as an argument to the Java interpreter
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Classes any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

Math an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface built-in class methods:
log(a) - natural logarithm of a
abs(a) - absolute value of a
max(a,b) - maximum of a and b
pow(a,b) - a to the bth power
sin(a) - sin of a radians
random() - a random number between 0.0 and 1.0

if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Example Classes any public class in other packages class 1 named package rather than the default package implementation for all its instance methods unless the class is abstract specification

nested class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class A class that is a member of another class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Classes any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

Object class an implements clause to declare that it contains methods for each of the operations specified by the interface some of the behaviour that every class in the Java system needs data associated with each object java.lang A class that is at the top of the class hierarchy
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the most general of all classes Objects any public class in other packages class 1 named package rather than the default package implementation for all its instance methods unless the class is abstract specification

programmer-created exception class its class using the getClass method use the new operator an implements clause to declare that it contains methods for each of the operations specified by the interface other objects by sending and receiving messages more than one interface
a real-world object
or an abstract concept
Exception class data associated with each object exception messages from
objects in the same process
objects in different processes
objects on the same machine
objects on different machines
messages to
objects in the same process
objects in different processes
objects on the same machine
objects on different machines
several different variables at the same time
if an exception is raised in a statement that is not in a try block with an appropriate catch statement
then Java looks to see if the caller of the current method is within a try block that has an appropriate catch block
if this is not successful, Java looks at callers right up to the main program
otherwise Java reports an error if it has not been able to find any suitable catch block
a class type whose instances are the values of the class type 0 or more condition variables the unit of data abstraction in an object-oriented program Exception Handling String name = new String(); any public class in other packages without reference to the instance variables contained in it methods from other objects using the 'private' keyword a string using the toString method itself to a string representation using the toString method 1 named package rather than the default package other objects that a condition variable has changed public interface
declaring and initializing it such that it is created whenever execution enters a particular block, or, in the case of an instance variable, when an instance is created, for example:
String aString = "some text";
or by declaring it and initializing it later using the new operator, for example:
String aString;
aString = new String("some text");
something goes wrong in the execution of a program implementation for all its instance methods unless the class is abstract one copy of each class variable of its class with the other instances of its class a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

public class outside its package an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface data associated with each object class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Classes any public class in other packages 1 named package rather than the default package implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

System an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface java.lang data associated with each object every program A class that is part of the API of Java and which provides system-independent access to system-dependent functionality
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program How Java Works any public class in other packages class 1 named package rather than the default package to provide system-independent access to system-dependent functionality implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

Thread class an implements clause to declare that it contains methods for each of the operations specified by the interface the Runnable interface thread data associated with each object A Java class that implements the general concept of a thread
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Threads any public class in other packages class start, run, interrupt, sleep, yield, join, stop (deprecated), suspend (deprecated) the java.lang package implementation for all its instance methods unless the class is abstract specification

wrapper class an implements clause to declare that it contains methods for each of the operations specified by the interface more than one interface instance of wrapper class useful class methods class
if a class is not declared public
then it is accessible only to members of the same package
a class type whose instances are the values of the class type the unit of data abstraction in an object-oriented program Classes primitive data type any public class in other packages 1 named package rather than the default package to allow you to do something with primitive values beyond what the basic operators can accomplish implementation for all its instance methods unless the class is abstract a unique name since somebody in the future might want to import the packages containing both classes and hence create a name clash

Next access unit: constructor Up: access unit, specification Previous access unit: variable