Java Programming

100 metres seems to be the length of a spool of gardeners cotton Discuss:How_long_is_a_piece_of_string...we are not talking about jute twine here!So the maximum length of a piece of string would be 999.99mm!So the real answer to 'how long is a piece of string?' would be...anything between 0.01mm to 999.99mm.

step 1:

create menubar object and set it

step 2:

create menu objects with parameterized constructor

step 3:

add menus to menubar

32 bits or 4 bytes and an int is not an address, it is a primitive so it directly access the data without a reference.

The two types of variables are the CONSTANT and CONTROL.

In one sense, since EEPROM is memory, you don't program memory. You store things in memory, and the thing you are programming in this case would likely be a micro-processor or micro-controller that is on the same circuit as the EEPROM.

In theory, an EEPROM is just memory, so any language that would be able to produce machine language output for the CPU type connected to the EEPROM in any instance could be used.

In practice, many programs written to EEPROM would be for embedded systems. In this case, a lower level language like C could be used, or a higher level language that output C or the right kind of assembly.

A higher level language like C# or Java would likely not be used, as the overhead of the virtual machine might be considered to be too heavy for a micro-controller, or small micro-processor.

That being said, in practice, you could use anything. But it is likely you would have some libraries in C or C++ that you might want to use, so you would likely use a language that was compatible with any libraries you might use.

yah it's correct.

java

The error "Connection reset by peer" is a TCP error that occurs when a server sends your application a RST (i.e. reset) packet which terminates the TCP connection between you and the server.

You can retry manually and maybe the server will not reset you, but if you keep getting this there is not much you can do. It is the equivalent of slamming the phone back on the hook abruptly instead of politely saying goodby and gently hanging up.

There is only one comma, but it is not used in switch-case. Character literals are between apostrophes: 'x'

JAVA beans and coffee beans are two very different things . JAVA beans are used to generate getters and setters. while coffee beans are use to make coffee.

Cyclic inheritance is physically impossible. A base class cannot inherit from one of its own derivatives any more than you could inherit some generic trait from one of your own descendants. Inheritance is strictly a one-way street.

Its an interface.

The easiest way to implement a calculator is an RPN calculator (enter the numbers first, perform the operation last). You need a last-in-first-out stack (there's a "stack" class in C++, but you can also implement your own using an array or a linked list), and a set of functions that pop the last elements from the stack and push the result (e.g. Add() pops the last 2 values and pushes their addition).
You'll need the math.h library for scientific operations.

ColumnModel columnModel = table.getColumnModel();

for(Column: columnModel.getColumns()) {

Column column = <FIND COLUMN YOU NEED>;

}

columnModel.removeColumn(column);

By no means; you can access any random array element. If you have ever seen examples which process them in order, it is because of the following: when the order doesn't matter (for example, you want to calculate the sum of all the array elements), it is easiest to process them in order.

The Java Runtime Environment (JRE) converts the byte code to machine language.

the main purpose of the legislation was to stabilize the black workforce by compelling African Americans to work and by limiting their economic options … The laws aimed to replace the social controls of slavery, which had been legally swept away by the Emancipation Proclamation and the Thirteenth Amendment, and to reinstate the substance of the slave system without the legal form.

No. not directly.

The static constructor is called by .net framework, not by your code.

I always treat static constructor is the class initializer (not the instance one). The initialization routine is only called when the class definition being loaded.

When the derived class is loaded, since this class derived from the base, it makes to go up the chain (of the hierarchy) to call those static constuctors.

So, when a derived class is loaded, the static constructors of the hierarchy is called up. (any one of them had been loaded, the calling sequence stops).

You cannot call those static constructor directly, nor you can skip "not to execute" them.

Yes. There is no specific order in which the compiler expects methods to be present. As long as the method is inside the class it is perfectly fine.

public boolean has2or3(int[] nums) {

if ( nums[0] 3 )

return true;

return false;

}

Yes using the equals method.

Example:

Double a = new Double(Double.NaN);

Double b = new Double(Double.NaN);

if( a.equals(b) )

System.out.println("True");

else

System.out.println("False");

If you execute the above code snippet you will see "True" in the console. If you try the "==" operator to compare the 2 values a and b you will get only false

public class Class1 {

protected InnerClass1 ic;

public Class1() {

ic = new InnerClass1();

}

public void displayStrings() {

System.out.println(ic.getString() + ".");

System.out.println(ic.getAnotherString() + ".");

}

static public void main(String[] args) {

Class1 c1 = new Class1();

c1.displayStrings();

}

protected class InnerClass1 {

public String getString() {

return "InnerClass1: getString invoked";

}

public String getAnotherString() {

return "InnerClass1: getAnotherString invoked";

}

}

}

we can do like . crieate inner class instanve in side of main class defalut consiter . use the object we do the our bz logic

// short version

char c = 'a';

System.out.println((c=='a'c=='e'c=='i'c=='o'c=='u')?"VOWEL":"CONSONANT");

// easy to read version

char c = 'a';

switch (c) {

case 'a':

case 'e':

case 'i':

case 'o':

case 'u':

System.out.println("VOWEL");

break;

default:

System.out.println("CONSONANT");

}

Mutator: Put something into the class (change something). By convention, has a name that starts with "set", for example, "getName".

Accessor: Get something out of the class (find out the class's state). By convention, has a name that starts with "get", for example, "getName". For logical values, "is" is used instead, for example, "isActive".

Can you answer in this java programming quiz? just 1 or 2 answers are fine..

1. The != operator is used to evaluate _______ between two values.

Non-equality

!!

=!

Equality

2. The interface part of a class is created using

package access

protected visibility

private visibility

3. User defined data type or objects (like a Car class object) are passed by

Reference

Value

Copy

Placement

5 . If you declare constructors private, they ________ be called by all classes and methods to create objects.

Can

can privately

can virtually

Can t

6. Components are placed in a container by calling the __________ method.

registerComponent ()

addActionListener ()

setLayout ()

add ()

7. If an abstract method is not defined in a subclass, the subclass is

Abstract

Overridden

Promoted to the superclass

Hidden

8. Subclass objects of different type that inherit from the same superclass

Can be treated as superclass objects

Can't share private superclass data

Don't share the same superclass data

Don't share any data

9. Polymorphism

Promotes and allows sharing of data and methods between classes

Allows development of general solutions and the runtime selection of methods

Prevents methods outside a class from directly accessing instance variables

Allows classes to contain/combine both data (properties) and methods (behaviors)

10. Inheritance relationships form _________.

Hierarchical Structures

Peer to Peer Networks

Loosely bounded sets

Network Structures

11. Your program class that inherits from JPanel ____________.

Uses a constructor to initialize objects

Inherits the behavior of a JObject program

Is unable to override paint_component ()

Knows nothing of drawing

12. The paint_component method ___________.

Must be private

Expects a Graphics object argument

Never calls super.paint_component (g)

Must be called by you

13. Successful use of polymorphism depends on

Identifying generic methods

Identifying an inheritance class composition

Identifying abstract objects

Deciding on how to use subclass references

14. A superclass method can be overridden in a subclass in order to

Change the name

Make the method private

Provide new behavior appropriate to the subclass

Allow hidden access

16 . In order to place subclass objects of different type in an array

They must inherit from the same subclass

The array reference itself must be of superclass type

You must cast and add-in missing superclass members

They must be of the same type

17. The name of the event handler method of the ActionListener interface is ____.

itemStateChanged

mouseMoved

actionPerformed +

keyPressed

18. Downcasting

Converts a subclass reference to a superclass reference

Converts a subclass object to a superclass object

Converts a superclass reference to a subclass reference

Converts a superclass object to a subclass object

19. A simple layout manager is the ____ manager.

GridLayout

BoxLayout

FlowLayout

PanelLayout

20. An individual array element is accessed using its _________.

Type

Subscript/Index

Value

Object

21. Since it generates byte codes, the Java compiler is _________.

An interpreter

Not a true compiler

Object code

Windows instructions

22. When GUI components are displayed on the screen, a/an ___________ positions and displays those components.

Layout manager

Container object

Event handler

Interface class

23. An executing program class must contain a/an

Body

Main method

Instance variable

Comment

24. Referring to a superclass object through a subclass reference

Can cause a runtime error

Requires that the superclass reference refers to the same subclass object as the cast

Requires an explicit object to avoid the compilation error

25. Polymorphism works for

Unrelated classes

Overloaded classes

An inheritance hierarchy of classes

Has-a classes

26. Given that a=4, b=10, c=2, d=5, and x=3, the expression "(a + c) / c * d + a" evaluates to

20

4

128

19+

27. When dynamic binding takes place, the Java system

Determines the type of the object at compile time

Binds a method name to its address at runtime

Moves up the inheritance hierarchy

Makes a list of generic event handlers

28. When dynamic binding takes place, the Java system

Determines the type of the object at compile time

Binds a method name to its address at runtime

Moves up the inheritance hierarchy

Makes a list of generic event handlers

29. If a subclass constructor explicitly calls a superclass constructor

It overrides the superclass constructor

It must call the noarg constructor

It cannot access protected data

The call must be the first line of code

30. The composition relationship can be identified as a/an _________ relationship.

Enduring

Has/a

Is/a

Overridden

31. When declared with a static lifetime,

Variables exist during the execution of a method

Variables exist from beginning to end of program execution

Methods and instance variables are visible

Variables declared outside the {} of a block

32. When an array is passed as an argument to a method, _____.

The array is passed by reference

Only the first value is passed

The called method can't change array values

It is passed by value

33. When the expression "result = total + input * 2;" is evaluated the __________ is placed in the location of the left hand side.

Left side result

Assignment

Right side result

Operator

34. When invoked, a subclass constructor

Automatically calls the noarg constructor of the superclass (if one is not explicitly called)

Cannot access superclass data even if protected

Returns a superclass object

Does not use the superclass constructor

35. When declared with automatic scope,

Variables exist during the execution of a method

Variables exist from beginning to end of program execution

Methods and instance variables are visible

Variables declared outside the {} of a block

36. The inheritance class relationship

Promotes and allows sharing of data and methods between classes

Allows development of general solutions and the runtime selection of methods

Prevents methods outside a class from directly accessing instance variables

Allows classes to contain/combine both data (properties) and methods (behaviors)

37. When a subclass method has the same name and type as a superclass method but accepts different arguments, that's an example of

Protected inheritance

Overriding

Polymorphism

Overloading

38. When you want to declare constant values, you would use the ________ keyword.

objects

final

const

Static variables

39. The toString method

Is not provided by class Object

Is called implicitly to convert an object to a String

Can be overloaded

Can't be overridden

40. A switch statement tests a variable or expression against __________.

Constant, integral values

Expressions

Decimal numbers

Strings

41. Reffering to a superclass object through a subclass reference

can cause a runtime error

Requires that the superclass reference refers to the same subclass object

Requires an explicit object to avoid the compilation error

48. Because all variables must be declared before their use, Java

Is an object oriented language

Is a strong variable language

Is a strongly typed language

Is a typing language

49. Variables declared/defined inside a method are

General variables

Visible everywhere

Local variables

Instance variables

50. The while statement

Is the most specific form of repetition

Requires initialization, test, and change of a control variable

Will never skip execution of the loop body

Doesn't use a control variable

51. The do-while statement

Does not require a test of cond

Is the most specific form of repetition

Executes at least once

Is intended to replace for statements

52. The use of superclass references to refer to subclass objects has been found useful

For container objects

When placing elements of subclass objects in a superclass array

When placing elements of superclass objects in a subclass array

For Composition classes

53. Overloaded constructors are used to

Create different types of objects

Create two dimensional arrays

Create primitive data types

Initialize objects of the same class in different ways

54. Java's mechanism for placing related classes in a subdirectory uses the ________ keyword.

package

import

extensible

extends

55. this

is a reference to an object

Can t be used to access object data

Is passed to every class

Is hidden and private

56. An anonymous inner class ____.

Has a class name

Typically is used to define an event handler class

Has no scope

Contains anonymous methods

57. The new operator is used to __________.

Allocate memory for an object or array

Call an object destructor

Call the garbage collector

Promote visibility

58. The drawOval method takes the same four arguments as ________.

drawLine ()

drawPoly ()

drawRect ()

fillArc ()

59. In order for a class method to access the private data of a class object (not of its class)

The data can only be read

It can't

The data can be changed directly

get/set methods must be used

Question 62

62. Class methods ________ access all class variables, public or private.

Can

Can't

64. A reference in a Java program

Causes object initialization

Refers or points to a runtime data type

Causes memory allocation

Refers (or points to) to an object

65. The listener interface for radio buttons is the ____ interface.

ActionListener

MouseListener

KeyListener

ItemListener

66. implementation part of a class is created using

67. What types of superclass methods/variables can be directly accessed from a sub class?

public

private

provoked

68. The statement(s) in the body of an if structure should be indented in order to

Compile properly

They shouldn t

Stand out and enhance readability

Allow repetition

69. The sdk program that is the JVM and runs programs is

java

javac

appletviewer