1
1 public class ComputeArea {
2
3 public static void main(String[] args){
4
5 double radius;
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7 double area;
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9 radius = 20;
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11 area = radius * radius * 3.14159;
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13 System.out.println("The area for the circle of radius " + radius + " is " + area);
14
15 }
16
17 }
18
19 //Output:The area for the circle of radius 20.0 is 1256.636
2
1 import java.util.Scanner;
2
3 public class ComputeAverage {
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5 public static void main (String[] args) {
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7 Scanner input = new Scanner(System.in);
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9 System.out.print("Enter three numbers: ");
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11 double number1 = input.nextDouble();
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13 double number2 = input.nextDouble();
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15 double number3 = input.nextDouble();
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17 double average = (number1 + number2 + number3) / 3;
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19 System.out.println("The average of " + number1 + " " + number2 + " "+ number3 + " is " + average);
20
21 }
22
23 }
24
25 /*Output:
26 Enter three numbers: 6 7 8
27 The average of 6.0 7.0 8.0 is 7.0*/
3
1 import java.util.Scanner; 2 public class ComputerAreaWithConsoleInput { 3 public static void main(String[] args){ 4 Scanner input = new Scanner(System.in); 5 System.out.print("Enter a number for radius: "); 6 double radius = input.nextDouble(); 7 double area = radius * radius *3.14159; 8 System.out.println("The area for the circle of radius " + radius + " is " + area); 9 } 10 } 11 /*output：Enter a number for radius: 30 12 The area for the circle of radius 30.0 is 2827.431*/
4
1 import java.util.Scanner; 2 public class DisplayTime { 3 public static void main(String[] args){ 4 Scanner input = new Scanner(System.in); 5 System.out.println("Enter an integer for seconds: "); 6 int seconds = input.nextInt(); 7 int minutes = seconds / 60; 8 int remainingSeconds = seconds % 60; 9 System.out.println(seconds + " seconds is " + minutes + " minutes and " + remainingSeconds + " seconds"); 10 } 11 } 12 /*output:Enter an integer for seconds: 13 500 14 500 seconds is 8 minutes and 20 seconds*/
5
1 import java.util.Scanner; 2 public class FahrenheitToCelsius { 3 public static void main(String[] args){ 4 Scanner input = new Scanner(System.in); 5 System.out.println("Enter a degree in Fahrenheit"); 6 double fahrenheit = input.nextDouble(); 7 double celsius = (5.0 / 9) * (fahrenheit - 32); 8 System.out.println("Fahrenheit " + fahrenheit + " is " + celsius + " in Celsius"); 9 } 10 } 11 /* 12 output:Enter a degree in Fahrenheit 13 70 14 Fahrenheit 70.0 is 21.11111111111111 in Celsius 15 */
6
1 public class ShowCurrentTime { 2 public static void main(String[] arga){ 3 long totalMilliseconds = System.currentTimeMillis(); 4 long totalSeconds = totalMilliseconds / 1000; 5 long currentSecond = (int)(totalSeconds % 60); 6 long totalMinutes = totalSeconds / 60; 7 long currentMinute = (int)(totalMinutes % 60); 8 long totalHours = totalMinutes / 60; 9 long currentHour = (int)(totalHours % 24); 10 System.out.println("Current time is " + currentHour + ":" + currentMinute + ":" + currentSecond + " GMT"); 11 } 12 } 13 //output:Current time is 13:14:55 GMT
7
1 import java.util.Scanner; 2 public class ComputeLoan { 3 public static void main(String[] args){ 4 Scanner input = new Scanner(System.in); 5 System.out.println("enter yearly interest rate, for example 8.25: "); 6 double annualInterestRate = input.nextDouble(); 7 double monthlyInterestRate = annualInterestRate / 1200; 8 System.out.print("Enter number of years as an integer, for example 5: "); 9 int numberOfYears = input.nextInt(); 10 System.out.print("Enter loan amount, for example 120000.95: "); 11 double loanAmount = input.nextDouble(); 12 double monthlyPayment = loanAmount * monthlyInterestRate / (1 - 1 / Math.pow(1 + monthlyInterestRate, numberOfYears * 12)); 13 double totalPayment = monthlyPayment * numberOfYears * 12; 14 System.out.println("The monthly payment is " + (int)(monthlyPayment * 100) / 100.0); 15 System.out.println("The total payment is " + (int)(totalPayment * 100) / 100.0); 16 } 17 } 18 /*output: 19 enter yearly interest rate, for example 8.25: 20 9 21 Enter number of years as an integer, for example 5: 7 22 Enter loan amount, for example 120000.95: 60000 23 The monthly payment is 965.34 24 The total payment is 81088.95 25 */
8
1 import javax.swing.JOptionPane; 2 public class DisplayUnicode { 3 public static void main(String[] args){ 4 JOptionPane.showMessageDialog(null,"\u6B22\u8FCE \u03b1 \u03b2 \u03b3", "\u6B22\u8FCE Welcome",JOptionPane.INFORMATION_MESSAGE); 5 } 6 }
9
1 import java.util.Scanner; 2 public class ComputeChange { 3 public static void main(String[] args) { 4 Scanner input = new Scanner(System.in); 5 System.out.print("Enter an amount in double, for example 11.56: "); 6 double amount = input.nextDouble(); 7 int remainingAmount = (int)(amount * 100); 8 int numberOfOneDollars = remainingAmount / 100; 9 remainingAmount = remainingAmount % 100; 10 int numberOfQuarters = remainingAmount / 25; 11 remainingAmount = remainingAmount % 25; 12 int numberOfDimes = remainingAmount / 10; 13 remainingAmount = remainingAmount % 10; 14 int numberOfNickels = remainingAmount / 5; 15 remainingAmount = remainingAmount % 5; 16 int numberOfPennies = remainingAmount; 17 String output = "Your amount " + amount + " consists of \n" + 18 "\t" + numberOfOneDollars + " dollars\n" + 19 "\t" + numberOfQuarters + " quarters\n" + 20 "\t" + numberOfDimes + " dimes\n" + 21 "\t" + numberOfNickels + " nickels\n" + 22 "\t" + numberOfPennies + " pennies"; 23 System.out.println(output); 24 } 25 } 26 /* 27 Enter an amount in double, for example 11.56: 90 28 Your amount 90.0 consists of 29 90 dollars 30 0 quarters 31 0 dimes 32 0 nickels 33 0 pennies 34 */
10
1 import javax.swing.JOptionPane; 2 public class ComputeLoanUsingInputDialog { 3 public static void main(String[] args){ 4 String annualInterestRateString = JOptionPane.showInputDialog("enter yearly interest rate, for example 8.25:"); 5 double annualInterestRate = Double.parseDouble(annualInterestRateString); 6 double monthlyInterestRate = annualInterestRate / 1200; 7 String numberOfYearsString = JOptionPane.showInputDialog("enter number of years as an integer, \nfor example 5:"); 8 int numberOfYears = Integer.parseInt(numberOfYearsString); 9 String loanString = JOptionPane.showInputDialog("Enter loan amount, for example 120000.95:"); 10 double loanAmount = Double.parseDouble(loanString); 11 double monthlyPayment = loanAmount * monthlyInterestRate / (1 - 1 / Math.pow(1 + monthlyInterestRate, numberOfYears * 12)); 12 double totalPayment = monthlyPayment * numberOfYears * 12; 13 monthlyPayment = (int)(monthlyPayment * 100); 14 totalPayment = (int)(totalPayment * 100) / 100.0; 15 String output = "the monthly payment is " + monthlyPayment + "\nythe total payment is " + totalPayment; 16 JOptionPane.showMessageDialog(null, output); 17 } 18 }
