Calculate Circle Area using radius

Calculate Circle Area using radius

By Unknown   12:29   No comments:

/*
 This program shows how to calculate
 area of circle using it's radius.
 */

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class CalculateCircleAreaExample {

    public static void main(String[] args) {
        int radius = 0;
        System.out.println("Please enter radius of a circle");
        try {
//get the radius from console
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            radius = Integer.parseInt(br.readLine());
        } //if invalid value was entered
        catch (NumberFormatException ne) {
            System.out.println("Invalid radius value" + ne);
            System.exit(0);
        } catch (IOException ioe) {
            System.out.println("IO Error :" + ioe);
            System.exit(0);
        }
        /*
         * Area of a circle is
         * pi * r * r
         * where r is a radius of a circle.
         */
//NOTE : use Math.PI constant to get value of pi
        double area = Math.PI * radius * radius;
        System.out.println("Area of a circle is " + area);
    }
}
/*
Output of Calculate Circle Area using Java Example would be

Please enter radius of a circle
19
Area of a circle is 1134.1149479459152
*/

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Nested Switch

Nested Switch

By Unknown   10:07   No comments:

/*
Statements Example
This example shows how to use nested switch statements in a
java program.
*/

public class NestedSwitchExample {

    public static void main(String[] args) {
        /*
         * Like any other Java statements, switch statements
         * can also be nested in each other as given in
         * below example.
         */
        int i = 0;
        int j = 1;
        switch (i) {
            case 0:
                switch (j) {
                    case 0:
                        System.out.println("i is 0, j is 0");
                        break;
                    case 1:
                        System.out.println("i is 0, j is 1");
                        break;

                    default:
                        System.out.println("nested default case ! ");
                }
                break;
            default:
                System.out.println("No matching case found!!");
        }
    }
}
/*
Output would be,
i is 0, j is 1
*/

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Reversed pyramid using for loops & decrement operator.

Reversed pyramid using for loops & decrement operator.

By Unknown   09:53   No comments:

/*
Pyramid 5 Example
This Java Pyramid example shows how to generate pyramid or triangle
like given below using for loop.
12345
1234
123
12
1
*/
public class JavaPyramid5 {

    public static void main(String[] args) {
        for (int i = 5; i > 0; i--) {
            for (int j = 0; j < i; j++) {
                System.out.print(j + 1);
            }
            System.out.println("");
        }
    }
}
/*
Output of the example would be
12345
1234
123
12
1
*/

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Pyramid of stars using nested for loops

Pyramid of stars using nested for loops

By Unknown   09:52   No comments:

/*
 Java Pyramid 1 Example
 This Java Pyramid example shows how to generate pyramid or triangle
 like given below using for loop.
 *
 **
 ***
 ****
 *****
 */

public class JavaPyramid1 {

    public static void main(String[] args) {
        for (int i = 1; i <= 5; i++) {
            for (int j = 0; j < i; j++) {
                System.out.print("*");
            }
//generate a new line
            System.out.println("");
        }
    }
}
/*
Output of the above program would be
*
**
***
****
*****
*/

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Generate prime numbers between 1 & given number

Generate prime numbers between 1 & given number

By Unknown   17:43   No comments:

/*
 Prime Numbers Java Example
 This Prime Numbers Java example shows how to generate prime numbers
 between 1 and given number using for loop.
 */

public class GeneratePrimeNumbersExample {

    public static void main(String[] args) {
//define limit
        int limit = 100;
        System.out.println("Prime numbers between 1 and " + limit);
//loop through the numbers one by one
        for (int i = 1; i < 100; i++) {
            boolean isPrime = true;
//check to see if the number is prime
            for (int j = 2; j < i; j++) {
                if (i % j == 0) {
                    isPrime = false;
                    break;
                }
            }
// print the number
            if (isPrime) {
                System.out.print(i + " ");
            }
        }
        
    }
}
/*
Output of Prime Numbers example would be
Prime numbers between 1 and 100
1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
*/

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Palindrome Number

Palindrome Number

By Unknown   17:42   No comments:

/*
 This program shows how to check for in the given list of numbers
 whether each number is palindrome or not
 */

public class JavaPalindromeNumberExample {

    public static void main(String[] args) {
//array of numbers to be checked
        int numbers[] = new int[]{121, 13, 34, 11, 22, 54};
//iterate through the numbers
        for (int i = 0; i < numbers.length; i++) {
            int number = numbers[i];
            int reversedNumber = 0;
            int temp = 0;
            /*
             * If the number is equal to it's reversed number, then
             * the given number is a palindrome number.
             *
             * For ex,121 is a palindrome number while 12 is not.
             */
//reverse the number
            while (number > 0) {
                temp = number % 10;
                number = number / 10;
                reversedNumber = reversedNumber * 10 + temp;
                
            }
            if (numbers[i] == reversedNumber) {
                System.out.println(numbers[i] + " is a palindrome");
            } else {
                System.out.println(numbers[i] + " not a palindrome ");
            }
        }
    }
}
/*
Output of Java Palindrome Number Example would be
121 is a palindrome number
13 is not a palindrome number
34 is not a palindrome number
11 is a palindrome number
22 is a palindrome number
54 is not a palindrome number
*/

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Fibonacci Series

Fibonacci Series

By Unknown   14:44   No comments:

/* Fibonacci Series Java Example
 This Fibonacci Series Java Example shows how to create and print
 Fibonacci Series using Java.
 */

public class JavaFibonacciSeriesExample {

    public static void main(String[] args) {
//number of elements to generate in a series
        int limit = 20;
        long[] series = new long[limit];
//create first 2 series elements
        
        series[0] = 0;
        series[1] = 1;
//create the Fibonacci series and store it in an array
        for (int i = 2; i < limit; i++) {
            series[i] = series[i - 1] + series[i - 2];
        }
//print the Fibonacci series numbers
        System.out.println("Fibonacci Series upto " + limit);
        for (int i = 0; i < limit; i++) {
            System.out.print(series[i] + " ");
        }
    }
}
/*
Output of the Fibonacci Series Java Example would be
Fibonacci Series upto 20
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181
*/

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Determine If Year Is Leap Year

Determine If Year Is Leap Year

By Unknown   14:41   No comments:

/*
Determine If Year Is Leap Year Java Example
This Determine If Year Is Leap Year Java Example shows how to
determine whether the given year is leap year or not.
*/
public class DetermineLeapYearExample {
    public static void main(String[] args) {

        //year we want to check
        int year = 2004;
        //if year is divisible by 4, it is a leap year
        if(year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))
            System.out.println("Year " + year + " is a leap year");
        else
            System.out.println("Year " + year + " is not a leap year");
    }
}
/*
Output of the example would be
Year 2004 is a leap year
*/

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Compare Two Numbers using else-if

Compare Two Numbers using else-if

By Unknown   12:19   No comments:

/*
 Compare Two Numbers Java Example
 This Compare Two Numbers Java Example shows how to compare two numbers
 using if else if statements.
 */

public class CompareTwoNumbers {

    public static void main(String[] args) {
//declare two numbers to compare
        int num1 = 324;
        int num2 = 234;
        if (num1 > num2) {
            System.out.println(num1 + " is greater than " + num2);
        } else if (num1 < num2) {

            System.out.println(num1 + " is less than " + num2);
        } else {
            System.out.println(num1 + " is equal to " + num2);
        }
    }
}
/*
Output of Compare Two Numbers Java Example would be
324 is greater than 234
*/

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Factorial of a number

Factorial of a number

By Unknown   12:17   No comments:

/*
 This program shows how to calculate
 Factorial of a number.
 */

public class NumberFactorial {

    public static void main(String[] args) {
        int number = 5;
        /*
         * Factorial of any number is! n.
         * For example, factorial of 4 is 4*3*2*1.
         */
        int factorial = number;
        for (int i = (number - 1); i > 1; i--) {
            4

        }
        {
            factorial = factorial * i;
        }
        System.out.println("Factorial of a number is " + factorial);
    }
}
/*
Output of the Factorial program would be
Factorial of a number is 120
*/

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