Java Programs:-

Table_Program.java

package java_programs;

import java.util.Scanner;

public class Table_Program {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int no = 0;

System.out.println("Enter the number : ");

no = sc.nextInt();

for (int i = 0; i < 10; i++) {

System.out.println(no + " * " + (i + 1) + " = " + (no * (i + 1)));

}

o/p:-

Enter the number :

3 * 1 = 3

3 * 2 = 6

3 * 3 = 9

3 * 4 = 12

3 * 5 = 15

3 * 6 = 18

3 * 7 = 21

3 * 8 = 24

3 * 9 = 27

3 * 10 = 30

Simple_Interest.java

package java_programs;

import java.util.Scanner;

public class Simple_Interest {

public static void main(String args[]) {

float p, r, t;

Scanner s = new Scanner(System.in);

System.out.print("Enter the Principal : ");

p = s.nextFloat();

System.out.print("Enter the Rate of interest : ");

r = s.nextFloat();

System.out.print("Enter the Time period : ");

t = s.nextFloat();

float si;

si = (r * t * p) / 100;

System.out.print("The Simple Interest is : " + si);

}

o/p:-

Enter the Principal : 5000

Enter the Rate of interest : 2

Enter the Time period : 12

The Simple Interest is : 1200.0

MultiplicationTable.java

package java_programs;

import java.util.Scanner;

public class MultiplicationTable {

public static void main(String args[]) {

int n, c;

System.out

.println("Enter an integer to print it's multiplication table");

Scanner in = new Scanner(System.in);

n = in.nextInt();

System.out.println("Multiplication table of " + n + " is : ");

for (c = 1; c <= 10; c++)

System.out.println(n + "*" + c + " = " + (n * c));

}// main()

}

o/p:-

Enter an integer to print it's multiplication table

Multiplication table of 2 is :

2*1 = 2

2*2 = 4

2*3 = 6

2*4 = 8

2*5 = 10

2*6 = 12

2*7 = 14

2*8 = 16

2*9 = 18

2*10 = 20

MilliSec.java

package java_programs;

import java.util.Date;

public class MilliSec {

public static void main(String[] args) {

long millis = System.currentTimeMillis();

Date date = new Date(millis);

System.out.println(date);

}

o/p:-

Sat Dec 08 15:04:17 IST 2018

GetMyIPAddress.java

package java_programs;

import java.net.InetAddress;

public class GetMyIPAddress {

public static void main(String args[]) throws Exception {

* public static InetAddress getLocalHost() throws UnknownHostException:

* Returns the address of the local host. This is achieved by retrieving

* the name of the host from the system, then resolving that name into

* an InetAddress. Note: The resolved address may be cached for a short

* period of time.

InetAddress myIP = InetAddress.getLocalHost();

* public String getHostAddress(): Returns the IP address string in

* textual presentation.

System.out.println("My IP Address is:");

System.out.println(myIP.getHostAddress());

}

o/p:-

My IP Address is:

192.168.136.1

EMI.java

package java_programs;

public class EMI {

// Function to calculate EMI

static float emi_calculator(float p, float r, float t) {

float emi;

r = r / (12 * 100); // one month interest

t = t * 12; // one month period

emi = (p * r * (float) Math.pow(1 + r, t))

/ (float) (Math.pow(1 + r, t) - 1);

return (emi);

}

// Driver Program

static public void main(String[] args) {

float principal, rate, time, emi;

principal = 10000;

rate = 10;

time = 2;

emi = emi_calculator(principal, rate, time);

System.out.println("Monthly EMI is = " + emi);

}

o/p:-

Monthly EMI is = 461.44965

Dicount.java

package java_programs;

import java.util.Scanner;

public class Dicount {

static void print(String line) {

System.out.println(line);

}

public static void main(String[] args) {

int price;

int discount;

Scanner sc = new Scanner(System.in);

print("Enter price of the product :");

price = sc.nextInt();

print("Enter Discount of the product :");

discount = sc.nextInt();

int finalPrice = (price * discount) / 100;

print("Final price is " + finalPrice);

}

}// class

o/p:-

Enter price of the product :

10000

Enter Discount of the product :

1000

Final price is 100000

Demo.java

package java_programs;

import java.util.Scanner;

//sum of first 10 natural num's:-

public class Demo {

public static void main(String[] args) {

int num, count, total = 0;

System.out.println("Enter the value of n:");

//Scanner is used for reading user input

Scanner scan = new Scanner(System.in);

//nextInt() method reads integer entered by user

num = scan.nextInt();

//closing scanner after use

scan.close();

for(count = 1; count <= num; count++){

total = total + count;

}

System.out.println("Sum of first "+num+" natural numbers is: "+total);

}

o/p:-

Enter the value of n:

Sum of first 3 natural numbers is: 6

DateExample.java

package java_programs;

import java.util.Date;

public class DateExample {

public static void main(String[] args) {

Date date = new Date();

System.out.println(date);

}

o/p:-

Sat Dec 08 15:09:42 IST 2018

Arrays:-

ArrayListDemo.java

package Arrays;

import java.util.ArrayList;

public class ArrayListDemo {

public static void main(String[] args) {

// create an empty array list with an initial capacity

ArrayList<String> arrlist = new ArrayList<String>(5);

// use add() method to add values in the list

arrlist.add("G");

arrlist.add("E");

arrlist.add("F");

arrlist.add("M");

System.out.println("Size of list: " + arrlist.size());

// let us print all the values available in list

for (String value : arrlist) {

System.out.println("Value = " + value);

}

// retrieving the index of element "E"

int retval = arrlist.indexOf("E");

System.out.println("The element E is at index " + retval);

}

o/p:-

Size of list: 4

Value = G

Value = E

Value = F

Value = M

The element E is at index 1

findPairClosestToZero.java

apackage Arrays;

import java.util.Arrays;

public class findPairClosestToZero {

public static void main(String[] args) {

int array[] = { 1, 30, -5, 70, -8, 20, -40, 60 };

findPairWithMinSumBruteForce(array);

findPairWithMinSum(array);

}

public static void findPairWithMinSumBruteForce(int arr[]) {

if (arr.length < 2)

return;

// Suppose 1st two element has minimum sum

int minimumSum = arr[0] + arr[1];

int pair1stIndex = 0;

int pair2ndIndex = 1;

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

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

int tempSum = arr[i] + arr[j];

if (Math.abs(tempSum) < Math.abs(minimumSum)) {

pair1stIndex = i;

pair2ndIndex = j;

minimumSum = tempSum;

}

System.out

.println(" The pair whose sum is closest to zero using brute force method: "

+ arr[pair1stIndex] + " " + arr[pair2ndIndex]);

}// findPairWithMinSumBruteForce

public static void findPairWithMinSum(int arr[]) {

// Sort the array, you can use any sorting algorithm to sort it

Arrays.sort(arr);

int sum = 0;

int minimumSum = Integer.MAX_VALUE;

int n = arr.length;

if (n < 0)

return;

// left and right index variables

int l = 0, r = n - 1;

// variables to keep track of the left and right index pair for

// minimumSum

int minLeft = l, minRight = n - 1;

while (l < r) {

sum = arr[l] + arr[r];

/* If abs(sum) is less than min sum, we need to update sum and pair */

if (Math.abs(sum) < Math.abs(minimumSum)) {

minimumSum = sum;

minLeft = l;

minRight = r;

}

if (sum < 0)

l++;

else

r--;

}

System.out.println(" The pair whose sum is minimun : " + arr[minLeft]

+ " " + arr[minRight]);

}// findPairWithMinSum

}

o/p:-

The pair whose sum is closest to zero using brute force method: 1 -5

The pair whose sum is minimun : -5 1

Java Program to check Even or Odd number

import java.util.Scanner;

class CheckEvenOdd
{
public static void main(String args[])
{
    int num;
    System.out.println("Enter an Integer number:");

    //The input provided by user is stored in num
    Scanner input = new Scanner(System.in);
    num = input.nextInt();

    /* If number is divisible by 2 then it's an even number
     * else odd number*/
    if ( num % 2 == 0 )
        System.out.println("Entered number is even");
     else
        System.out.println("Entered number is odd");
}
}

Output 1:

Enter an Integer number:
78
Entered number is even

Java program to swap two numbers

● Java program to swap two numbers using a temporary variable.

● To swap numbers without using extra variable

Swapping using temporary or third variable:

import java.util.Scanner;

class SwapNumbers
{
   public static void main(String args[])
   {
      int x, y, temp;
      System.out.println("Enter x and y");
      Scanner in = new Scanner(System.in);

      x = in.nextInt();
      y = in.nextInt();

      System.out.println("Before Swapping\nx = "+x+"\ny = "+y);

      temp = x;
      x = y;
      y = temp;

      System.out.println("After Swapping\nx = "+x+"\ny = "+y);
   }
}

Swap numbers program class file.

Output of program:

Swapping without temporary variable

import java.util.Scanner;

class SwapNumbers
{
   public static void main(String args[])
   {
      int x, y;
      System.out.println("Enter x and y");
      Scanner in = new Scanner(System.in);

      x = in.nextInt();
      y = in.nextInt();

      System.out.println("Before Swapping\nx = "+x+"\ny = "+y);

      x = x + y;
      y = x - y;
      x = x - y;

      System.out.println("After Swapping\nx = "+x+"\ny = "+y);
   }
}

Java Program to Calculate Area of Rectangle

import java.util.Scanner;
class AreaOfRectangle {
   public static void main (String[] args)
   {
         Scanner scanner = new Scanner(System.in);
         System.out.println("Enter the length of Rectangle:");
         double length = scanner.nextDouble();
         System.out.println("Enter the width of Rectangle:");
         double width = scanner.nextDouble();
         //Area = length*width;
         double area = length*width;
         System.out.println("Area of Rectangle is:"+area);
   }
}

Output:

Enter the length of Rectangle:
2
Enter the width of Rectangle:
8
Area of Rectangle is:16.0

Java program to calculate area of Square

import java.util.Scanner;
class SquareAreaDemo {
   public static void main (String[] args)
   {
       System.out.println("Enter Side of Square:");
       //Capture the user's input
       Scanner scanner = new Scanner(System.in);
       //Storing the captured value in a variable
       double side = scanner.nextDouble();
       //Area of Square = side*side
       double area = side*side;
       System.out.println("Area of Square is: "+area);
   }
}

Output:

Enter Side of Square:
2.5
Area of Square is: 6.25

Java program to calculate area of Triangle

import java.util.Scanner;
class AreaTriangleDemo {
   public static void main(String args[]) {
      Scanner scanner = new Scanner(System.in);

      System.out.println("Enter the width of the Triangle:");
      double base = scanner.nextDouble();

      System.out.println("Enter the height of the Triangle:");
      double height = scanner.nextDouble();

      //Area = (width*height)/2
      double area = (base* height)/2;
      System.out.println("Area of Triangle is: " + area);
   }
}

Output:

Enter the width of the Triangle:
2
Enter the height of the Triangle:
2
Area of Triangle is: 2.0

Java Program to calculate area and circumference of circle

import java.util.Scanner;
class CircleDemo
{
   static Scanner sc = new Scanner(System.in);
   public static void main(String args[])
   {
      System.out.print("Enter the radius: ");
      /*We are storing the entered radius in double
       * because a user can enter radius in decimals
       */
      double radius = sc.nextDouble();
      //Area = PI*radius*radius
      double area = Math.PI * (radius * radius);
      System.out.println("The area of circle is: " + area);
      //Circumference = 2*PI*radius
      double circumference= Math.PI * 2*radius;
      System.out.println( "The circumference of the circle is:"+circumference) ;
   }
}

Output:

Enter the radius: 1
The area of circle is: 3.141592653589793
The circumference of the circle is:6.283185307179586

Java program to generate random number

In the below program, we are using the nextInt() method of Random class to serve our purpose.

import java.util.*;
class GenerateRandomNumber {
   public static void main(String[] args) {
      int counter;
      Random rnum = new Random();
      /* Below code would generate 5 random numbers
       * between 0 and 200.
       */
      System.out.println("Random Numbers:");
      System.out.println("***************");
      for (counter = 1; counter <= 5; counter++) {
         System.out.println(rnum.nextInt(200));
      }
   }
}

Output:

Random Numbers:
***************
135
173
5
17
15

Java Program to display first n or first 100 prime numbers

Program to display first n prime numbers

import java.util.Scanner;

class PrimeNumberDemo
{
   public static void main(String args[])
   {
      int n;
      int status = 1;
      int num = 3;
      //For capturing the value of n
      Scanner scanner = new Scanner(System.in);
      System.out.println("Enter the value of n:");
      //The entered value is stored in the var n
      n = scanner.nextInt();
      if (n >= 1)
      {
         System.out.println("First "+n+" prime numbers are:");
         //2 is a known prime number
         System.out.println(2);
      }

      for ( int i = 2 ; i <=n ; )
      {
         for ( int j = 2 ; j <= Math.sqrt(num) ; j++ )
         {
            if ( num%j == 0 )
            {
               status = 0;
               break;
            }
         }
         if ( status != 0 )
         {
            System.out.println(num);
            i++;
         }
         status = 1;
         num++;
      }
   }
}

Output:

Enter the value of n:
15
First 15 prime numbers are:
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47

Java program to sum the elements of an array

Program: User enters the array’s elements

/**
* @author: BeginnersBook.com
* @description: User would enter the 10 elements
* and the program will store them into an array and
* will display the sum of them.
*/
import java.util.Scanner;
class SumDemo{
   public static void main(String args[]){
      Scanner scanner = new Scanner(System.in);
      int[] array = new int[10];
      int sum = 0;
      System.out.println("Enter the elements:");
      for (int i=0; i<10; i++)
      {
      array[i] = scanner.nextInt();
      }
      for( int num : array) {
          sum = sum+num;
      }
      System.out.println("Sum of array elements is:"+sum);
   }
}

Output:

Enter the elements:
1
2
3
4
5
6
7
8
9
10
Sum of array elements is:55

Java Program to check Leap Year

import java.util.Scanner;
public class Demo {

    public static void main(String[] args) {

    int year;
    Scanner scan = new Scanner(System.in);
    System.out.println("Enter any Year:");
    year = scan.nextInt();
    scan.close();
        boolean isLeap = false;

        if(year % 4 == 0)
        {
            if( year % 100 == 0)
            {
                if ( year % 400 == 0)
                    isLeap = true;
                else
                    isLeap = false;
            }
            else
                isLeap = true;
        }
        else {
            isLeap = false;
        }

        if(isLeap==true)
            System.out.println(year + " is a Leap Year.");
        else
            System.out.println(year + " is not a Leap Year.");
    }
}

Output:

Enter any Year:
2001
2001 is not a Leap Year.

Java Program to read integer value from the Standard Input

We have imported the package java.util.Scanner to use the Scanner. In order to read the input provided by user, we first create the object of Scanner by passing System.in as parameter. Then we are using nextInt() method of Scanner class to read the integer.

import java.util.Scanner;

public class Demo {

    public static void main(String[] args) {

        /* This reads the input provided by user
         * using keyboard
         */
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter any number: ");

        // This method reads the number provided using keyboard
        int num = scan.nextInt();

        // Closing Scanner after the use
       scan.close();

        // Displaying the number
        System.out.println("The number entered by user: "+num);
    }
}

Output:

Enter any number: 101
The number entered by user: 101

Program to convert char to String

We have following two ways for char to String conversion.

Method 1: Using toString() method

Method 2: Usng valueOf() method

class CharToStringDemo
{
   public static void main(String args[])
   {
      // Method 1: Using toString() method
      char ch = 'a';
      String str = Character.toString(ch);
      System.out.println("String is: "+str);

      // Method 2: Using valueOf() method
      String str2 = String.valueOf(ch);
      System.out.println("String is: "+str2);
   }
}

Output:

String is: a
String is: a

Converting String to Char

We can convert a String to char using charAt() method of String class.

class StringToCharDemo
{
   public static void main(String args[])
   {
      // Using charAt() method
      String str = "Hello";
      for(int i=0; i<str.length();i++){
        char ch = str.charAt(i);
        System.out.println("Character at "+i+" Position: "+ch);
      }
   }
}

Output:

Character at 0 Position: H
Character at 1 Position: e
Character at 2 Position: l
Character at 3 Position: l
Character at 4 Position: o

Program to find sum of first n (entered by user) natural numbers

import java.util.Scanner;
public class Demo {

    public static void main(String[] args) {

        int num, count, total = 0;


        System.out.println("Enter the value of n:");
        //Scanner is used for reading user input
        Scanner scan = new Scanner(System.in);
        //nextInt() method reads integer entered by user
        num = scan.nextInt();
        //closing scanner after use
        scan.close();
        for(count = 1; count <= num; count++){
            total = total + count;
        }

        System.out.println("Sum of first "+num+" natural numbers is: "+total);
    }
}

Output:

Enter the value of n:
20
Sum of first 20 natural numbers is: 210

Find Largest Number in Array using Collections

1. import java.util.*;

2. public class LargestInArrayExample2{

3. public static int getLargest(Integer[] a, int total){

4. List<Integer> list=Arrays.asList(a);

5. Collections.sort(list);

6. int element=list.get(total-1);

7. return element;

8. }

9. public static void main(String args[]){

10. Integer a[]={1,2,5,6,3,2};

11. Integer b[]={44,66,99,77,33,22,55};

12. System.out.println("Largest: "+getLargest(a,6));

13. System.out.println("Largest: "+getLargest(b,7));

14. }}

Largest: 6
Largest: 99

Find Smallest Number in Array using Collections

1. import java.util.*;

2. public class SmallestInArrayExample2{

3. public static int getSmallest(Integer[] a, int total){

4. List<Integer> list=Arrays.asList(a);

5. Collections.sort(list);

6. int element=list.get(0);

7. return element;

8. }

9. public static void main(String args[]){

10. Integer a[]={1,2,5,6,3,2};

11. Integer b[]={44,66,99,77,33,22,55};

12. System.out.println("Smallest: "+getSmallest(a,6));

13. System.out.println("Smallest: "+getSmallest(b,7));

14. }}

Smallest: 1
Smallest: 22

Q)Palindrome number

Palindrome number in java: A palindrome number is a number that is same after reverse. For example 545, 151, 34543, 343, 171, 48984 are the palindrome numbers. It can also be a string like LOL, MADAM etc.

1. import java.util.*;

2. class PalindromeExample2

3. {

4. public static void main(String args[])

5. {

6. String original, reverse = ""; // Objects of String class

7. Scanner in = new Scanner(System.in);

8. System.out.println("Enter a string/number to check if it is a palindrome");

9. original = in.nextLine();

10. int length = original.length();

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

12. reverse = reverse + original.charAt(i);

13. if (original.equals(reverse))

14. System.out.println("Entered string/number is a palindrome.");

15. else

16. System.out.println("Entered string/number isn't a palindrome.");

17. }

18. }

Q)Factorial

Factorial Program in Java: Factorial of n is the product of all positive descending integers. Factorial of n is denoted by n!. For example:

1. 4! = 4*3*2*1 = 24

2. 5! = 5*4*3*2*1 = 120

The factorial is normally used in Combinations and Permutations (mathematics).

There are many ways to write the factorial program in java language.

● Factorial Program using loop

● Factorial Program using recursion

using loop

1. class FactorialExample{

2. public static void main(String args[]){

3. int i,fact=1;

4. int number=5;//It is the number to calculate factorial

5. for(i=1;i<=number;i++){

6. fact=fact*i;

7. }

8. System.out.println("Factorial of "+number+" is: "+fact);

9. }

10. }

using recursion

1. class FactorialExample2{

2. static int factorial(int n){

3. if (n == 0)

4. return 1;

5. else

6. return(n * factorial(n-1));

7. }

8. public static void main(String args[]){

9. int i,fact=1;

10. int number=4;//It is the number to calculate factorial

11. fact = factorial(number);

12. System.out.println("Factorial of "+number+" is: "+fact);

13. }

14. }

Q)BubbleSort

We can create a java program to sort array elements using bubble sort. Bubble sort algorithm is known as the simplest sorting algorithm.

In bubble sort algorithm, array is traversed from first element to last element. Here, current element is compared with the next element. If current element is greater than the next element, it is swapped.

1. public class BubbleSortExample {

2. static void bubbleSort(int[] arr) {

3. int n = arr.length;

4. int temp = 0;

5. for(int i=0; i < n; i++){

6. for(int j=1; j < (n-i); j++){

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

8. //swap elements

9. temp = arr[j-1];

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

11. arr[j] = temp;

12. }

13.

14. }

15. }

16.

17. }

18. public static void main(String[] args) {

19. int arr[] ={3,60,35,2,45,320,5};

20.

21. System.out.println("Array Before Bubble Sort");

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

23. System.out.print(arr[i] + " ");

24. }

25. System.out.println();

26.

27. bubbleSort(arr);//sorting array elements using bubble sort

28.

29. System.out.println("Array After Bubble Sort");

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

31. System.out.print(arr[i] + " ");

32. }

33.

34. }

35. }

Output:

Array Before Bubble Sort
3 60 35 2 45 320 5
Array After Bubble Sort
2 3 5 35 45 60 320

Linear search is used to search a key element from multiple elements. Linear search is less used today because it is slower than binary search and hashing.

You can also use a method where array is not predefined. Here, user has to put the elements as input and select one element to check its location.

1. import java.util.Scanner;

3. class LinearSearchExample2

4. {

5. public static void main(String args[])

6. {

7. int c, n, search, array[];

9. Scanner in = new Scanner(System.in);

10. System.out.println("Enter number of elements");

11. n = in.nextInt();

12. array = new int[n];

13.

14. System.out.println("Enter those " + n + " elements");

15.

16. for (c = 0; c < n; c++)

17. array[c] = in.nextInt();

18.

19. System.out.println("Enter value to find");

20. search = in.nextInt();

21.

22. for (c = 0; c < n; c++)

23. {

24. if (array[c] == search) /* Searching element is present */

25. {

26. System.out.println(search + " is present at location " + (c + 1) + ".");

27. break;

28. }

29. }

30. if (c == n) /* Element to search isn't present */

31. System.out.println(search + " isn't present in array.");

32. }

33. }

34.

Binary search is used to search a key element from multiple elements. Binary search is faster than linear search.

In case of binary search, array elements must be in ascending order. If you have unsorted array, you can sort the array using Arrays.sort(arr) method.

Let's see an example of binary search in java.

1. class BinarySearchExample{

2. public static void binarySearch(int arr[], int first, int last, int key){

3. int mid = (first + last)/2;

4. while( first <= last ){

5. if ( arr[mid] < key ){

6. first = mid + 1;

7. }else if ( arr[mid] == key ){

8. System.out.println("Element is found at index: " + mid);

9. break;

10. }else{

11. last = mid - 1;

12. }

13. mid = (first + last)/2;

14. }

15. if ( first > last ){

16. System.out.println("Element is not found!");

17. }

18. }

19. public static void main(String args[]){

20. int arr[] = {10,20,30,40,50};

21. int key = 30;

22. int last=arr.length-1;

23. binarySearch(arr,0,last,key);

24. }

25. }

Binary Search Example in Java using Arrays.binarySearch()

1. import java.util.Arrays;

2. class BinarySearchExample2{

3. public static void main(String args[]){

4. int arr[] = {10,20,30,40,50};

5. int key = 30;

6. int result = Arrays.binarySearch(arr,key);

7. if (result < 0)

8. System.out.println("Element is not found!");

9. else

10. System.out.println("Element is found at index: "+result);

11. }

12. }

Element is found at index: 2

Java Blog

Pages

Programs

Java program to swap two numbers

Swapping using temporary or third variable:

Swapping without temporary variable

Java Program to Calculate Area of Rectangle

Java program to calculate area of Square

Java program to calculate area of Triangle

Java Program to calculate area and circumference of circle

Java program to generate random number

Java Program to display first n or first 100 prime numbers

Java program to sum the elements of an array

Java Program to check Leap Year

Java Program to read integer value from the Standard Input

Program to convert char to String

Converting String to Char

Program to find sum of first n (entered by user) natural numbers

Find Largest Number in Array using Collections

Find Smallest Number in Array using Collections

using loop

using recursion

Binary Search Example in Java using Arrays.binarySearch()

No comments:

Post a Comment

Report Abuse