Java Swing - Finding diameter and circumfernce a circle

  

               The program calculates the diameter ( by multiplying the radius by 2), and then calculates the circumference (by multiplying the diameter by 3.14). The program prints both the diameter and the circumference.

Java code:

import java.text.DecimalFormat;

import javax.swing.JOptionPane;

public class I_C_2 

{

    public static void main (String args[])

    

    {

        // Declaring  variables

        String radius_strg;

        double radius,diameter, cirm;

        double pi = 3.14;

        DecimalFormat formatter = new DecimalFormat("#.00");

        

        // Prompt user to input by dialogbox

        radius_strg = JOptionPane.showInputDialog(null,"Enter Radius: ");

        

        // Convert string value into double

        radius = Double.parseDouble(radius_strg);

        

        // Compile diameter

        diameter = radius * 2;

        

        // Compile circumfernce

        cirm = diameter * pi;

        

        // Output : Displaying the result diameter and circumfernce in Message Dialogbox

        JOptionPane.showMessageDialog(null," The Diameter is " + formatter.format(diameter) + "\n\r" + "The Circumfence is " + formatter.format(cirm));

        

        } // end of the main clause

     } // end of the program

Result : Click me for result

Simple Array, Simple Forloop

 Printing  numbers by using array and forloop methods in Java


Java Code:


public class I_C_6 {

    public static void main(String[] arg) {
        int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9};
        for (int i = 0; i < 9; i++) {
            System.out.println(numbers[i]);
        }

    }
}

Screenshot:

Simple Java Forloop

Printing Numbers by using For loop(Simple Forloop)

public class ForLoop
{
    public static void main (String args[])
    {
 
        for ( int i=1; i <8; i++)
        {
            System.out.println("The count is : " +i);
        }
    }
}

Java question & answer

Java sample questions and answers

Question 1

1.  

The following pseudocode is an example of a(n) ____ structure:  get firstNumber  get secondNumber  add firstNumber and secondNumber  print result

Answer

		sequence
		decision
		loop
		nested

Question 2

1.  

The following pseudocode is an example of a(n) ____ structure:  if firstNumber is bigger than secondNumber then    print firstNumber  else    print secondNumber

		sequence
		decision
		loop
		nested

  

Question 3

1.  

Fill in the blank in the following pseudocode:if someCondition is true then   do oneProcess____   do theOtherProcess

		then
		while
		do
		else

Question 4

1.  

The following pseudocode is an example of a(n) ____ structure:  get number  while number is positive    add to sum    get number

		sequence
		decision
		loop
		nested

Question 5

1.  

The statement that best describes the following pseudocode is: ____.if conditionA is true then  do stepEelse  do stepB  if conditionF is true then    while conditionI is true      do stepJ    endwhile  else    do stepG  endif do stepDendif

Answer

		A decision is nested in a sequence
		A decision is nested in a loop
		A loop is nested in a decision that is nested in another decision
		A sequence is nested inside a decision nested in another decision

Question 6

1.  

The following pseudocode reads a number from the user, multiplies it by 2 and prints the result. The ____ program statement should replace the ? to make this program functional and structured.  get inputNumber  while not eof       calculatedAnswer = inputNumber * 2       print calculatedAnswer       ?  endwhile

		no statement is needed
		if done then exit
		get inputNumber
		print inputNumber

Question 7

1.  

Years ago, programmers could avoid using structure by inserting a “____” statement into their pseudocode.

		loop
		go next
		next
		go to

Question 8

1.  

Structured programs can be easily broken down into routines or ____ that can be assigned to any number of programmers.

		segments
		modules
		units
		sequences

 

Question 9

1.  

The following pseudocode might be rewritten using a(n) ____ structure:if class = "Freshman" then  tuitionFee = 75else  if class = "Sophomore" then    tuitionFee = 50  else    if class = "Junior" then      tuitionFee = 30    else      tuitionFee = 10    endif  endifendif

		if-then-else
		case
		while
		do while

Question 10

1.  

____ is the process of paying attention to important properties while ignoring nonessential details.

Answer

		Abstraction
		Modularization
		Reusability
		Direction

 

Question 11

1.  

____ is the feature of programs that assures you a module has been tested and proven to function correctly.

		Modularization
		Abstraction
		Reliability
		Reusability

Question 12

1.  

In a flowchart, you draw each module separately with its own sentinel symbols. The symbol that is the equivalent of the start symbol in a program contains the ____.

		id of the module
		name of the module
		description of the module
		name of the program

Question 13

1.  

When a program or module uses another module, you can refer to the main program as the ____ program.

		director
		calling
		called
		parent

Question 14

1.  

The computer keeps track of the correct memory address to which it should return after executing a module by recording the memory address in a location known as the ____.

		flowchart
		pointer
		stack
		set

Question 15

1.  

A variable that is used known to the entire program is a ____ variable.

		local
		shared
		non-modular
		global

Question 16

1.  

When declaring a variable in languages such as Visual Basic, C++, Java and C#, the ____ must be identified.

		variable name only
		variable data type only
		variable name and data type
		variable name, data type, and purpose

Question 17

1.  

The structure that is used in a binary selection is ____.

		if-then
		if-then-else
		while
		do-while

Question 18

1.  

The statement that best describes the following pseudocode is ____.if hoursWorked > 40 then    grossPay = 40 * rate + (hoursWorked - 40) * 1.5 * rateelse    grossPay = hoursWorked * rateendif

Answer

		dual-alternative selection
		unary selection
		case structure
		if-then structure

Question 19

1.  

Boolean expressions are named after ____.

Answer

		Harold Boolean
		Henry Boole
		George Boole
		Gerhardt Boolean

Question 20

1.  

The decision structure that is logically equivalent to the following is ___.if customerCode not equal to 1 then    discount = 0.25else    discount = 0.50endif

Answer

		if customerCode > 1 then    discount = 0.50else    discount = 0.25 endif
		if customerCode < 1 then    discount = 0.50else    discount = 0.25 endif
		if customerCode = 1 then    discount = 0.50else    discount = 0.25 endif
		if customerCode = 1 then    discount = 0.20else    discount = 0.50 endif

Question 21

1.  

Assume that out of 1,000 salespeople, 900 sell more than three items in a pay period, and only 500 sell items valued at $1000 or more. How many total questions must be asked in the following pseudocode to evaluate bonuses for 1000 salespeople?if itemsSold > 3 then     if valueSold >= 1000 then          bonusGiven = BONUS     endifendif

		100
		900
		1000
		1900

Question 22

1.  

For maximum efficiency, a good rule of thumb in an OR decision is to ____.

		first ask the question that is more likely to be true
		first ask the question that is more likely to be false
		rewrite as an and decision and ask the question more likely to be true
		rewrite as an and decision and ask the question more likely to be false

Question 23

1.  

The symbol that represents a logical OR in Perl, Java, C++, and C# is ____.

		%
		$
		||
		^

Question 24

1.  

The logical AND operator can be compared to ____ in terms of precedence.

		addition
		subtraction
		multiplication
		division

Question 25

1.  

The logical OR operator can be compared to ____ in terms of precedence.

		addition
		subtraction
		multiplication
		division

Question 26

1.  

The piece of pseudocode that represents incrementing the loop control variable is ____.

		rep = 1
		rep = rep + 1
		while (rep < 5)
		print “warning”

 

Question 27

1.  

In the following pseudocode fragment, the while loop will terminate when ____. 
counter = 10while response = ‘Y’     
print counter     counter = counter - 1     
print “Do you want to see the next counter? Y or N”    
 get response
endwhile

		counter = 0
		the while loop will not terminate.
		response = ‘Y’
		response = ‘N’

Question 28

1.  

In the following pseudocode, the statement print questionCounter will be executed ____ times.num PARTS = 5
num QUESTIONS = 3
partCounter = 1
while partCounter <= PARTS    
questionCounter = 1     
while questionCounter <= QUESTIONS         
 print questionCounter          
questionCounter = questionCounter + 1     
endwhile     partCounter = partCounter + 1endwhile

		0
		3
		5
		15

Question 29

1.  

What is wrong with the following?  rep = 10  while (rep < 20)    print “error”  endwhile

		loop control variable is not initialized
		loop control variable is not altered
		loop control variable is not declared
		loop body is missing

Question 30

1.  

In a for loop, a(n) ____ value is used to control how the loop control variable is incremented.

		step
		group
		id
		sentinel

Question 31

1.  

The statement that is true of a structured loop is that ____.

		the loop can exit from any point
		the loop body must execute at least once
		the loop condition represents the only exit from the loop
		the loop can repeat an infinite number of times

 

Question 32

1.  

An array is a(n) ____ of variables in memory.

		list
		accumulation
		set
		record

 

Question 33

1.  

The number of elements in an array is called the ____ of the array.

		width
		size
		height
		depth

Question 34

1.  

All of the elements in an array have the same ____.

		subscript
		name
		memory location
		value

 

Question 35

1.  

An array can be used to replace ____.

		records
		methods
		nested decisions
		loops

Question 36

1.  

Another name for a two dimensional  array is a(n) ____.

		vector
		table
		collection
		set

Question 37

1.  

The array that follows is an array ofdouble[] grades = new double[3];

		grades
		doubles
		objects
		arrays

 

Question 38

1.  

Which of the following is an invalid list of elements in an array?

		"Joe", "Doug", "Anne"
		"Joe", 3, 25.5
		3, 17, 12
		12.3, 32.6, 21.7

  

Question 39

1.  

What numbers does the code that follows print to the console?int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9};for (int i = 0; i < 9; i++){    System.out.println(numbers[i]);}

		0-9
		1-9
		1-8
		0-8
		0-9

   

Question 40

1.  

The length of the array that follows isint[] grades = new int[4];

		0
		3
		4
		5

  

Question 41

1.  

What is the value of names[4] in the following array?String[] names = {"Jeff", "Dan", "Sally", "Jill", "Allie"};

		Sally
		Jill
		Allie
		name[4] doesn’t exist

 

Question 42

1.  

What is the value of times[2][1] in the array that follows?double[][] times = { {23.0, 3.5}, {22.4, 3.6}, {21.3, 3.7} };

 

		3.7
		22.4
		3.5
		21.3
		3.6

 

Question 43

1.  

How many rows are in the array that follows?Rental[][] transactions = new Rental[7][3];

		7
		6
		3
		2

  

Question 44

1.  

What is the value of nums[2] after the following statements are executed?int[] values = {2, 3, 5, 7, 9};int[] nums = values;values[2] = 1;

		3
		1
		5
		0

Question 45

1.  

Consider the following condition. It will be true when(!(endProgram.equalsIgnoreCase("n")))

		the value of endProgram equals “n”
		the value of end Program equals “n” or “N”
		the value of endProgram doesn’t equal “n”
		the value of endProgram doesn’t equal “n” or “N”

 

Question 46

1.  

Which of the following statements do you use to jump to the top of an outer loop from an inner loop?

		continue
		labeled continue
		break
		labeled break

Question 47

1.  

How many lines are printed on the console when the following for loop is executed?for (int i = 2; i < 10; i++){    System.out.println(i);}

		8
		9
		10
		7

   

Question 48

1.  

How many lines are printed on the console when the following for loop is executed?for (int j = 10; j < 40; j *= 2) {    System.out.println(j);}

		1
		2
		3
		4

 

Question 49

1.  

How many lines are printed on the console when the following for loops are executed?for (int i = 1; i < 5; i += 2){    for (int j = 0; j < i; j++)    {        System.out.println(j);    }}

		2
		4
		5
		20

Question 50

1.  

Assume that the variable named entry has a starting value of 9 and number has a value of 3. What is the value of entry after the following statements are executed?if ((entry > 9) || (entry/number == 3))    entry--;else if (entry == 9)     entry++;else    entry = 3;

		3
		8
		9
		10

 

 -------------------------------------------------------------

Answers:

• Question 1

	The following pseudocode is an example of a(n) ____ structure:   get firstNumber   get secondNumber   add firstNumber and secondNumber   print result
	Answer:    sequence

• Question 2

	The following pseudocode is an example of a(n) ____ structure:   if firstNumber is bigger than secondNumber then     print firstNumber   else     print secondNumber
	Answer:    decision

• Question 3

	Fill in the blank in the following pseudocode: if someCondition is true then    do oneProcess ____    do theOtherProcess Answer
	else

• Question 4

	The following pseudocode is an example of a(n) ____ structure:   get number   while number is positive     add to sum     get number Answer
	loop

• Question 5

	The statement that best describes the following pseudocode is: ____. if conditionA is true then   do stepE else   do stepB   if conditionF is true then     while conditionI is true       do stepJ     endwhile   else     do stepG   endif do stepD endif
	Answer:    A loop is nested in a decision that is nested in another decision

• Question 6

2 out of 2 points

	The following pseudocode reads a number from the user, multiplies it by 2 and prints the result. The ____ program statement should replace the ? to make this program functional and structured.   get inputNumber   while not eof        calculatedAnswer = inputNumber * 2        print calculatedAnswer        ?   endwhile Answer
	get inputNumber

• Question 7

	Years ago, programmers could avoid using structure by inserting a “____” statement into their pseudocode. Answer
	go to

• Question 8

	Structured programs can be easily broken down into routines or ____ that can be assigned to any number of programmers.
	Answer: modules

• Question 9

	The following pseudocode might be rewritten using a(n) ____ structure: if class = "Freshman" then   tuitionFee = 75 else   if class = "Sophomore" then     tuitionFee = 50   else     if class = "Junior" then       tuitionFee = 30     else       tuitionFee = 10     endif   endif endif Answer
	case

• Question 10

	____ is the process of paying attention to important properties while ignoring nonessential details. Answer
	Abstraction

• Question 11

	____ is the feature of programs that assures you a module has been tested and proven to function correctly. Answer
	Reliability

• Question 12

	In a flowchart, you draw each module separately with its own sentinel symbols. The symbol that is the equivalent of the start symbol in a program contains the ____. Answer
	:    name of the module

• Question 13

	When a program or module uses another module, you can refer to the main program as the ____ program. Answer
	calling

• Question 14

	The computer keeps track of the correct memory address to which it should return after executing a module by recording the memory address in a location known as the ____. Answer
	stack

 

	A variable that is used known to the entire program is a ____ variable. Answer
	global

• Question 16

	When declaring a variable in languages such as Visual Basic, C++, Java and C#, the ____ must be identified. Answer
	variable name and data type

• Question 17

	The structure that is used in a binary selection is ____. Answer
	if-then-else

• Question 18

	The statement that best describes the following pseudocode is ____. if hoursWorked > 40 then     grossPay = 40 * rate + (hoursWorked - 40) * 1.5 * rate else     grossPay = hoursWorked * rate endif Answer
	dual-alternative selection

• Question 19

2 out of 2 points

	Boolean expressions are named after ____. Answer
	George Boole

• Question 20

	The decision structure that is logically equivalent to the following is ___. if customerCode not equal to 1 then     discount = 0.25 else     discount = 0.50 endif Answer
	if customerCode = 1 then     discount = 0.50 else     discount = 0.25 endif

• Question 21

	Assume that out of 1,000 salespeople, 900 sell more than three items in a pay period, and only 500 sell items valued at $1000 or more. How many total questions must be asked in the following pseudocode to evaluate bonuses for 1000 salespeople? if itemsSold > 3 then      if valueSold >= 1000 then           bonusGiven = BONUS      endif endif Answer
	1900

• Question 22

	For maximum efficiency, a good rule of thumb in an OR decision is to ____.
	Answer:    first ask the question that is more likely to be true

• Question 23

	The symbol that represents a logical OR in Perl, Java, C++, and C# is ____. Answer
	:    ||

• Question 24

	The logical AND operator can be compared to ____ in terms of precedence.
	Answer:    multiplication

• Question 25

	The logical OR operator can be compared to ____ in terms of precedence.
	Answer:    addition

• Question 26

2 out of 2 points

	The piece of pseudocode that represents incrementing the loop control variable is ____.
	Answer:    rep = rep + 1

• Question 27

	In the following pseudocode fragment, the while loop will terminate when ____. counter = 10 while response = ‘Y’      print counter      counter = counter - 1      print “Do you want to see the next counter? Y or N”      get response endwhile
	Answer:    response = ‘N’

• Question 28

	In the following pseudocode, the statement print questionCounter will be executed ____ times. num PARTS = 5 num QUESTIONS = 3 partCounter = 1 while partCounter <= PARTS      questionCounter = 1      while questionCounter <= QUESTIONS           print questionCounter           questionCounter = questionCounter + 1      endwhile      partCounter = partCounter + 1 endwhile
	Answer:    15

• Question 29

	What is wrong with the following?   rep = 10   while (rep < 20)     print “error”   endwhile
	Answer:    loop control variable is not altered

• Question 30

	In a for loop, a(n) ____ value is used to control how the loop control variable is incremented.
	Answer:    step

• Question 31

	The statement that is true of a structured loop is that ____.
	Answer:    the loop condition represents the only exit from the loop

• Question 32

	An array is a(n) ____ of variables in memory. Answer
	Answer    list

• Question 33

2 out of 2 points

	The number of elements in an array is called the ____ of the array.
	Answer:    size

• Question 34

	All of the elements in an array have the same ____.
	Answer:    name

• Question 35

	An array can be used to replace ____.
	Answer: nested decisions

• Question 36

	Another name for a two dimensional  array is a(n) ____.
	Answer:    table

• Question 37

	The array that follows is an array of double[] grades = new double[3];
	Answer:    doubles

• Question 38

	Which of the following is an invalid list of elements in an array?
	Answer:    "Joe", 3, 25.5

• Question 39

	What numbers does the code that follows print to the console? int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9}; for (int i = 0; i < 9; i++) {     System.out.println(numbers[i]); }
	Answer:    1-9

• Question 40

	The length of the array that follows is int[] grades = new int[4];
	Answer:    4

• Question 41

	What is the value of names[4] in the following array? String[] names = {"Jeff", "Dan", "Sally", "Jill", "Allie"};
	Answer:    Allie

• Question 42

	What is the value of times[2][1] in the array that follows? double[][] times = { {23.0, 3.5}, {22.4, 3.6}, {21.3, 3.7} };
	Answer:    3.7

• Question 43

	How many rows are in the array that follows? Rental[][] transactions = new Rental[7][3];
	Answer:    7

• Question 44

	What is the value of nums[2] after the following statements are executed? int[] values = {2, 3, 5, 7, 9}; int[] nums = values; values[2] = 1;
	Answer:    1

• Question 45

	Consider the following condition. It will be true when (!(endProgram.equalsIgnoreCase("n")))
	Answer:    the value of endProgram doesn’t equal “n” or “N”

• Question 46

	Which of the following statements do you use to jump to the top of an outer loop from an inner loop?
	Answer:    labeled continue

• Question 47

	How many lines are printed on the console when the following for loop is executed? for (int i = 2; i < 10; i++) {     System.out.println(i); }
	Answer:    8

• Question 48

	How many lines are printed on the console when the following for loop is executed? for (int j = 10; j < 40; j *= 2) {     System.out.println(j); }
	Answer:    2

• Question 49

	Answer:    4

• Question 50

	Assume that the variable named entry has a starting value of 9 and number has a value of 3. What is the value of entry after the following statements are executed? if ((entry > 9) || (entry/number == 3))     entry--; else if (entry == 9)     entry++; else     entry = 3;
	Answer:    8

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