1. Fibonacci series without using recursion
2. Fibonacci series using recursion

• Program:

class Main {
  public static void main(String[] args) {

    int n = 10, firstTerm = 0, secondTerm = 1;
    System.out.println("Fibonacci Series till " + n + " terms:");

    for (int i = 1; i <= n; ++i) {
      System.out.print(firstTerm + ", ");

      // compute the next term
      int nextTerm = firstTerm + secondTerm;
      firstTerm = secondTerm;
      secondTerm = nextTerm;
    }
  }
}

• Output:

Fibonacci Series till 10 terms:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34,

• Program:

public class MultiplicationTable {

    public static void main(String[] args) {

        int num = 8;
        for(int i = 1; i <= 10; ++i)
        {
            System.out.printf("%d * %d = %d \n", num, i, num * i);
        }
    }
}

• Output:

8 * 1 = 8 
8 * 2 = 16 
8 * 3 = 24 
8 * 4 = 32
8 * 5 = 40
8 * 6 = 48
8 * 7 = 56
8 * 8 = 64
8 * 9 = 72
8 * 10 = 80

• Program:

import java.math.BigInteger;

public class Factorial {

    public static void main(String[] args) {

        int num = 11;
        BigInteger factorial = BigInteger.ONE;
        for(int i = 1; i <= num; ++i)
        {
            // factorial = factorial * i;
            factorial = factorial.multiply(BigInteger.valueOf(i));
        }
        System.out.printf("Factorial of %d = %d", num, factorial);
    }
}

Factorial of 11 = 39916800

• Java program to find the sum of the first 100 natural numbers
• Java program to find the sum of n natural numbers
• Java program to find the sum of n natural numbers using the function

• Program:

public class SumNatural {

    public static void main(String[] args) {

        int num = 110, sum = 0;

        for(int i = 1; i <= num; ++i)
        {
            // sum = sum + i;
            sum += i;
        }

        System.out.println("Sum = " + sum);
    }
}

• Output:

Sum = 6105

• Program:

public class Alphabet {

    public static void main(String[] args) {

        char c = '-';

        if( (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
            System.out.println(c + " is an alphabet.");
        else
            System.out.println(c + " is not an alphabet.");
    }
}

• Output:

- is not an alphabet.

----- OR -----

n is an alphabet.

----- OR -----

V is an alphabet.

• If a number is less than zero, then it is a negative number
• If a number is greater than zero, then it is a negative number
• If a number is equal to zero, then it is neither negative nor positive number

• Program:

public class PositiveNegative {

    public static void main(String[] args) {

        double number = 11.1;

        // true if number is less than 0
        if (number < 0.0)
            System.out.println(number + " is a negative number.");

        // true if number is greater than 0
        else if ( number > 0.0)
            System.out.println(number + " is a positive number.");

        // if both test expression is evaluated to false
        else
            System.out.println(number + " is 0.");
    }
}

• Output:

11.1 is a positive number.

----- OR -----

-11.1 is a negative number.