Basic Programs using Java

I have shared some of the basic programs written in Java. Please see below and practice them with eclipse or any IDE. If you prefer to run it in a separate JVM you can do that as well. Here I have shared the samples written using eclipse.
Please click on the images to see an enlarged version.

1. Fibonacci Series

package com.techietamizhan.basicprograms;

public class FibonacciSeries {

           

            public static void main(String[] args) {

                        getFibonacciSeries(10);

            }

            public static void getFibonacciSeries(int count) {

                        int a = 0;

                        int b = 1;

                        int c = 1;

                        for (int i = 1; i <= count; i++) {

                                    System.out.println(a);

                                    a = b;

                                    b = c;

                                    c = a + b;

                        }

            }

} 

2.Reversing a String

package com.techietamizhan.basicprograms;

public class ReverseString {

            public static void main(String[] args) {

                        System.out.println(reverseString("techietamizhan"));

            }

            public static String reverseString(String str) {

                        if (str == null)

                                    return null;

                        StringBuilder out = new StringBuilder();

                        int length = str.length();

                        for (int i = length - 1; i >= 0; i--) {

                                    out.append(str.charAt(i));

                        }

                        return out.toString();

            }

}

3. Checking a Prime Number

package com.techietamizhan.basicprograms;

import java.util.Scanner;

public class PrimeNumberCheck {

            public static void main(String[] args) {

                        Scanner s = new Scanner(System.in);

                        System.out.print("Enter a number :");

                        int n = s.nextInt();

                        s.close();

                        checkPrimeNumber(n);

            }

            private static void checkPrimeNumber(int n) {

                        if (n == 0 || n == 1) {

                                    System.out.println(n + " is not a prime number");

                                    return;

                        }

                        if (n == 2) {

                                    System.out.println(n + " is a prime number");

                        }

                        for (int i = 2; i <= n / 2; i++) {

                                    if (n % i == 0) {

                                                System.out.println(n + " is not a prime number");

                                                return;

                                    }

                        }

                        System.out.println(n + " is a prime number");

            }

}

4. Checking a Palindrome

package com.techietamizhan.basicprograms;

import java.util.Scanner;

public class PalindromeCheck {

            public static void main(String[] args) {

                        Scanner s = new Scanner(System.in);

                        System.out.println("Enter a String:");

                        String str = s.next();

                        s.close();

                        checkPalindrome(str);

            }

            private static void checkPalindrome(String str) {

                        char[] charArray = str.toCharArray();

                        StringBuilder sb = new StringBuilder();

                        for (int i = charArray.length - 1; i >= 0; i--) {

                                    sb.append(charArray[i]);

                        }

                        if (sb.toString().equalsIgnoreCase(str))

                                    System.out.println(str + " is palindrome.");

                        else

                                    System.out.println(str + " is not a palindrome");

            }

           

}

5. Sorting an Array using Bubble Sort

package com.techietamizhan.basicprograms;

import java.util.Arrays;

public class ArraySort {

            public static void main(String[] args) {

                        int[] array = {20,50,40,10,60,30,20};           

                        int[] sortedArray = bubbleSort(array);                      

                        System.out.println(Arrays.toString(sortedArray));

            }

            public static int[] bubbleSort(int[] arr){

        int temp;

        for(int i=0; i < arr.length-1; i++){            

            for(int j=1; j < arr.length-i; j++){

                //the last index has highest value in first loop,second last index has second last highest value and so on

                if(arr[j-1] > arr[j]){

                    temp=arr[j-1];

                    arr[j-1] = arr[j];

                    arr[j] = temp;

                }

            }

            //uncomment the following line to see array after each iteration

            //System.out.println("Array after "+(i+1)+"th iteration:"+Arrays.toString(arr));

        }

        return arr;

    }

}

Any doubts or challenges please feel free to comment.