Saturday, September 16, 2023

10 Programming questions and exercises for Java Programmers

If you have just started learning the basics of Java programming language or are familiar with programming in either C or C++, then these Java programming questions and exercises are for you. It doesn't focus on a particular part of Java, but these coding exercises will switch you into programming mode. These are also great ways to master basic programming construct like if-else, loops like for and while break and continue with loop,   Java operators e.g., arithmetic and logical operator, recursion, methods, or functions, and standard Java API. You may also find these Java programming questions in most Java courses taught in schools, colleges, and various Java training courses.

Even I have started learning Java by doing these exercises multiple times in different ways. They are interesting, give a feeling of accomplishment if you complete them. These Java programs look simple, but they are still tricky for novice Java programmers. 

Try to solve these coding exercises by yourself but if you are stuck you can check relevant links or, of course, use google to get more insight into them. You can also see here more Java programming questions, and exercises.

And, If you need to refresh your Data Structure and algorithm skills to solve these Programming questions and exercise then check out Data Structures and Algorithms: Deep Dive Using Java course on Udemy. It's a great course to brush up on essential data structures like an array, linked list, binary tree, hash table, stack, queue, and basic techniques like recursion, dynamic programming, greedy algorithms, etc. 





Java Programing Questions exercises for beginners to practices

Here is my list of 10 Java programming questions or Java programs that can help any beginner to get started in the programming world. These are classics, popular, and very effective. You can use either notepad or any Java IDE like Eclipse or Netbeans for coding. See links for solutions and hints.

1. Write a program in Java to check if a number is even or odd in Java? (input 2 output true, input 3: output false)
A number is called even if it is completely divisible by two and odd if it's not entirely divisible by two. For example, the number 4 is an even number because when you do 4/2, the remainder is 0, which means 4 is completely divisible by 2. 

On the other hand, 5 is an odd number because 5/2 will result in the remainder as 1. See here to find how to check even and odd numbers in Java.



2. Write a program in Java to find out if a number is prime in Java? (input 7: output true, input 9: output false)
A number is called prime if it is divisible by either itself or 1. There are many algorithms to find prime numbers like, instead of dividing till number, division up to the square root of a number may be enough. Start from the simplest one and then try to solve this problem in a couple of different ways. Here is one way to check prime numbers in Java




3. Write a Java program to check if a number is a palindrome in Java? ( 121 is a palindrome, 321 is not)
A number is called a palindrome if the number is equal to the reverse of a number e.g., 121 is a palindrome because the reverse of 121 is 121 itself. On the other hand, 321 is not a palindrome because the reverse of 321 is 123, which is not equal to 321. See here for a solution of checking if a number is a palindrome or not in Java.


Practice questions and exercises for Java Beginners



4. How to find if a number is the power of 2 in Java? (1,2, 4 power of 2, 3 is not)
This is another interesting Java programming exercise. This program can be solved using different ways like using arithmetic operators or by using a bit shift operator.



5. Write a program to sort an integer array without using API methods?
Good Java programming questions and exercises for programmersSorting questions are one of the integral parts of programming questions. There are many sorting algorithms out there to sort an array in Java e.g. Bubble sort, Insertion sort, Selection sort, or quicksort. Implementing a sorting algorithm itself is a good programming exercise in Java. By the way, here is one way to sort an integer array with a Bubble sort algorithm in Java.



6. Write a Java program to check if a number is Armstrong's number or not? (input 153 output true,  123 output false)
An Armstrong number of 3 digits is a number for which the sum of cube of its digits is equal to a number e.g., 371 is an Armstrong number because of 3*3*3 + 7*7*7 + 1*1*1 = 371). See here for a sample Java program to check if a number is an Armstrong number or not.



7. Write a program in Java to reverse any String without using StringBuffer?
This is another classical Java programming question. You can reverse String in various way in Java, but two programming technique is used to do e.g. Iteration and Recursion. Try solving this problem using Iteration first by using Java's arithmetic operator and then look to implement a recursive solution. Here is one way to reverse String in Java without using StringBuffer.


Programming Practice questions and exercises for Java Programmers




8. Write a program in Java to print the Fibonacci series up to a given number? Write both iterative and recursive versions.
Fibonacci series is a popular number series and a very popular programming question in Java, in which the number is equal to the sum of the previous two numbers, starting from the third. Fibonacci series is also a good recursion exercise and is often asked in interviews as well. 

Try doing this exercise by using both Iterations like loops and recursion. For help, see How to print the Fibonacci series in Java using recursion

And, if you want to master the patterns on how to solve a problem using recursion etc, I suggest you check out 
Grokking the Coding Interview: Patterns for Coding Questions course on Educative, it's a great course to level up your coding skill also. 


programming questions and exercises for Beginners




9. Write a Java program to calculate the Factorial of an integer number? Both iterative and recursive solutions.
Calculating Factorial is also a classic recursion exercise in programming. Since Factorial is a recursive function, recursion becomes a natural choice to solve this problem. You just need to remember the formula for calculating Factorial, which is for n! its n*(n-1)*…1. Here is one way to calculate Factorial in Java using recursion.


10. Print following structure in Java?
This program is a good exercise for mastering loops e.g. for loop and while loop in Java. This also teaches you How to use the break and continue statement with loops in Java. By the way, you can print any character and use System.out.print() and System.out.println())
*
***
*****
***
*
Here is another similar programming exercise:

Programming questions and exercises for Java Programmers



These were some programming questions and exercises for beginners learning the Java programming language. This list is simple, and you can solve these coding exercises in any programming language. I am sure Java beginners will find these exercises interesting and useful. You can also post any coding exercise which you think can help junior programmers to learn to program and help to convert logic to code.


Other Coding Problems and Programming articles you may like
  • How to remove an element from the array without using a third-party library (check here)
  • 10 Free Courses to learn Data Structure and Algorithms (courses)
  • 30+ array Practice Questions for Java Programmers (questions)
  • How to find the largest and smallest number in an array in Java (read here)
  • 30+ linked list based Practice Questions for Java Programmers (questions)
  • Difference between array and ArrayList in Java (see here)
  • 40+ binary tree Practice problems for Java Programmers (questions)
  • How to loop over an array in Java (read here)
  • 50+ Data Structure Practice exercises for Java Programmers (questions)
  • 4 ways to sort array in Java (see here)
  • 100+ Data Structure and Algorithms Problems (solved)
  • How to convert Array to String in Java (read here)
  • How to print array in Java with examples (read here)
  • How to declare and initialize a multi-dimensional array in Java (see here)
  • How to compare two arrays in Java (check here)
  • 10 Books to learn Data Structure and Algorithms (books)
  • How to find two maximum numbers on an integer array in Java (check here)
  • Top 10 Courses to learn Data Structure and Algorithms in Java (courses)


Thanks for reading this article so far. If you like these Programming questions and exercises for Java Programmers then please share them with your friends and colleagues. If you have any doubts or feedback then please drop a note. 

P. S. - If you are looking for some Free Algorithms courses to improve your understanding of Data Structure and Algorithms, then you should also check the Data Structure in Java free course on Udemy. It's completely free, and all you need to do is create a free Udemy account to enroll in this course.


And, now one question for you, what is your favorite coding exercise from this one? Factorial, Pattern based problem, Palindrome or Armstrong number? or anything else, do let me know in comments. 

58 comments:

  1. These are good Java programming exercises for beginners but for experienced programmer its too simple. I would rather give complex application to develop to experienced programmer in couple of hours rather than simple programming exercise.

    ReplyDelete
    Replies
    1. can you send me please some complex program exercise on my email:arun.rout31@gmail.com plz plzzz

      Delete
    2. yes why not dude. please contact me via mustafaaftab2624@gmail.com

      Delete
    3. i have a doubt! Is there any way of iterating through strings in java without using predefs??

      Delete
    4. Hello Thiru, what is predefs? never heard about it?

      Delete
  2. To the previous commenter, even for experienced programmers some of these problems are still usefull to sharpen your skills with. A solid base will improve your overall ability and infact research into finding an efficint method of finding the factorial of an integer is still being conducted, if I'm not mistaken.

    ReplyDelete
  3. A good one would be to create an alarm clock that can work in both letters and numbers. Another would be fixing code for a program you garbled. Still, these are good school style exercises! Thank you.

    ReplyDelete
  4. I was looking for some beginners Java questions for my training course. I loved your collection, they are not too difficult, easy to understand but only thing is that they lack novelty. They are quite old Java questions. Though I would like to use these, I am also putting my own e.g.

    1) Write a Java program to get all hashtags and mentioned in a twitter message? (This would be a good String matching exercise in Java, as you can use regular expression, can split string etc. As hashtags starts with '#' and mentioned strats with '@' character.

    2) Count How many characters a String contains, without including any white space e.g. \t \n etc.

    ReplyDelete
  5. Admin can you post more Java programs which are used for improving programming skill and also useful for interviews(these 10 questions are good but want more and more like such questions friend....)

    ReplyDelete
  6. Exercise 10 for anyone interested, simple version.

    public class pyramidDrawing {

    public static void main(String[] args) {

    simpleDrawing(10);
    arrayDrawing(10);

    }


    public static void simpleDrawing(int number) {
    for(int i = 1; i <= number; i++) {
    for(int j = 1; j <= i; j++) {
    System.out.print("*");
    }
    System.out.println();
    }
    for(int v = number; v >= 1; v--) {
    for(int q = 1; q <= v; q++) {
    System.out.print("*");
    }
    System.out.println();
    }
    }


    public static void arrayDrawing(int number) {
    List numere = new ArrayList();

    for(int numar = 1 ; numar <= number; numar++) {
    numere.add(numar);
    }

    for(int i = 0; i < numere.size(); i++) {
    if(i % 2 == 0) {
    for(int j = 0; j <= i; j++) {
    System.out.print(numere.get(i));
    }
    System.out.println();
    }
    }

    for(int v = numere.size(); v >= 0; v--) {
    if(v % 2 != 0) {
    for(int q = 1; q <= v; q++) {
    System.out.print(numere.get(v-1));
    }
    System.out.println();
    }
    }
    }
    }

    ReplyDelete
    Replies
    1. *
      **
      ***
      ****
      *****
      ******
      *******
      ********
      *********
      **********
      **********
      *********
      ********
      *******
      ******
      *****
      ****
      ***
      **
      *
      1
      333
      55555
      7777777
      999999999
      999999999
      7777777
      55555
      333
      1

      Delete
    2. Updated one, as we no need to repeat the biggest number of stars or number for example 999999999, and also the argument in simpleDrawing(10) has to be 1,3,5,7,9,11or so on not 10
      import java.util.ArrayList;
      import java.util.List;

      public class pyramidDrawing {

      public static void main(String[] args) {

      simpleDrawing(7);
      arrayDrawing(10);

      }


      public static void simpleDrawing(int number) {
      for(int i = 1; i <= number; i+=2) {
      for(int j = 1; j <= i; j++) {
      System.out.print("*");
      }
      System.out.println();
      }
      for(int v = number-2; v >= 1; v-=2) {
      for(int q = 1; q <= v; q++) {
      System.out.print("*");
      }
      System.out.println();
      }
      }


      public static void arrayDrawing(int number) {
      List numere = new ArrayList();

      for(int numar = 1 ; numar <= number; numar++) {
      numere.add(numar);
      }

      for(int i = 0; i < numere.size(); i++) {
      if(i % 2 == 0) {
      for(int j = 0; j <= i; j++) {
      System.out.print(numere.get(i));
      }
      System.out.println();
      }
      }

      for(int v = numere.size()-2; v >= 0; v--) {
      if(v % 2 != 0) {
      for(int q = 1; q <= v; q++) {
      System.out.print(numere.get(v-1));
      }
      System.out.println();
      }
      }
      }
      }

      Delete
    3. just a question, you cant put more than 8 digits as the largest no. of digits for double (largest data type according to my knowledge, being only a 10th grade novice) right?

      Delete
  7. Dear admin,please give me the answer of no6..

    ReplyDelete
    Replies
    1. import java.util.Scanner;

      public class ArmstrongNumber {

      public static void main(String[] args)
      {
      int org, temp , sum = 0 , r;

      Scanner in = new Scanner(System.in);
      System.out.println("Enter the number to find its armstrong number or not");
      org = in.nextInt();

      // System.out.println(org);
      temp = org;

      while (temp != 0)
      {
      r =temp % 10;

      sum = sum +(r*r*r);

      temp = temp - r;

      temp = temp / 10;
      }

      if (org == sum)
      {
      System.out.println("the number " + org+ " is armstrong number");

      }

      else
      {
      System.out.println("the number " + org+ " is not armstrong number");

      }

      }

      }

      Delete
    2. public class ArmstrongNo {
      public static void main(String args[]) {
      double n,a,b,c,d,e,f;
      double g,h;
      System.out.print("enter n");
      n=TextIO.getInt();
      g=n/100;
      a=Math.floor(g);
      d=n-100*a;
      h=d/10;
      b=Math.floor(h);
      e=d-10*b;
      c=e;
      f=Math.pow(a,3)+Math.pow(b,3)+Math.pow(c,3);
      if (f==n){
      System.out.println("Yes");
      }
      else {
      System.out.println("No");
      }
      }}

      Delete
  8. My solution for part 4, im a beginner.

    import java.util.Scanner;
    public class Tutorial {

    public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.println("compare if Power of 2");
    while(true){
    System.out.println("Input your number:");
    double num = sc.nextInt();

    double power=1;
    int j=0;
    for(int i=0;i<100;i++){
    power=Math.pow(2, i);
    //System.out.println("num = "+power);
    if (num==power){
    j++;
    }


    }
    if (j>0){
    System.out.println("IS a power of 2");
    }
    else
    System.out.println("NOT a power of 2");




    }
    }
    }

    ReplyDelete
    Replies
    1. if you try to keep dividing the number by 2 and the number perfectly divided by 2 with 0 as remainder until you get 1 in the end then it is power of 2 otherwise it is not.

      import java.util.Scanner;

      public class PowerOfTwo {

      public static void main(String[] args) {
      // TODO Auto-generated method stub
      Scanner scan = new Scanner(System.in);
      int num = scan.nextInt();
      while(num%2==0 && num!=0)
      {
      num = num/2;
      }
      if(num == 1)
      System.out.println("Number is power of 2");
      else
      System.out.println("Number is not power of 2");
      }

      }

      Delete
  9. Too easy programs...........

    ReplyDelete
  10. A Dynamic Solution:
    public class PrintStructure {


    public static final int START = 1;
    public static final int MAX = 10;
    public static final int STEP_SIZE = 3;

    public static void main(String[] args) {

    int noOfLoops = (MAX - START) / STEP_SIZE;
    noOfLoops++;
    int noOfPrintingStars = START;
    boolean startDecreasing = false;
    for (int i = 0; i < (noOfLoops * 2 - 1); i++) {


    for (int j = 0; j < noOfPrintingStars; j++) {

    System.out.print("*");
    }
    System.out.println();

    if (startDecreasing) {
    noOfPrintingStars = noOfPrintingStars - STEP_SIZE;

    } else {
    noOfPrintingStars = noOfPrintingStars + STEP_SIZE;
    }
    if (noOfPrintingStars == MAX) {
    startDecreasing = true;
    }
    }
    }
    }

    ReplyDelete
  11. 3. Write a program that reads from the user four integers representing the numerators and denominators of two fractions, calculates the results of the two fractions and displays the values of the fractions sum, subtraction, multiplication and division.

    ReplyDelete
  12. 3. Write a program that reads from the user four integers representing the numerators and denominators of two fractions, calculates the results of the two fractions and displays the values of the fractions sum, subtraction, multiplication and division.

    Sample run:
    Enter the numerator and denominator of the first fraction: 6 4
    Enter the numerator and denominator of the second fraction: 8 5
    The sum is: 3.1
    The subtraction is: -0.1
    The multiplication is: 2.4
    The division is: 0.9375

    ReplyDelete
  13. 2. Write a program that reads in from the user an integer (num) between 1000 and 9999. Then it prompts the user to enter an integer (d) between 0 and 9 and a character (ch). Your program should replace the second and the last digit in num with d and it should display the character that precedes (ch) followed by the number after the change and then the character that comes after (ch). Use the division and modulus operators to extract the digits from num.

    Sample run:
    Enter an integer between 1000 and 9999: 2134
    Enter a digit (between 0 and 9): 6
    Enter a character: b
    Number was 2134. Result: a2636c.

    ReplyDelete
    Replies
    1. import java.io.*;
      import java.text.*;

      public class Fraction
      {
      public static void main(String a[])throws IOException
      {
      DataInputStream r = new DataInputStream(System.in);

      System.out.print("Enter the numerator and denominator of the first fraction : ");
      String firstNum = r.readLine();

      System.out.print("Enter the numerator and denominator of the second fraction : ");
      String secondNum = r.readLine();

      ComputeFraction cf = new ComputeFraction(firstNum,secondNum);

      System.out.println("The sum is: " + cf.getSum());
      System.out.println("The subtraction is: " + cf.getDiff());
      System.out.println("The multiplication is: " + cf.getProduct());
      System.out.println("The division is: " + cf.getQuotient());
      }
      }



      class ComputeFraction
      {
      DecimalFormat df = new DecimalFormat("#.##");
      double num1;
      double num2;

      public ComputeFraction(String firstNum, String secondNum)
      {
      String arr1[] = firstNum.split(" ");
      String arr2[] = secondNum.split(" ");

      num1 = Double.parseDouble(arr1[0]) / Double.parseDouble(arr1[1]);
      num2 = Double.parseDouble(arr2[0]) / Double.parseDouble(arr2[1]);
      }

      public double getSum()
      {
      return Double.parseDouble(df.format(num1+num2));
      }

      public double getDiff()
      {
      return Double.parseDouble(df.format(num1-num2));
      }

      public double getProduct()
      {
      return Double.parseDouble(df.format(num1*num2));
      }

      public double getQuotient()
      {
      return Double.parseDouble(df.format(num1/num2));
      }
      }

      Delete
    2. Solution for Question 2:

      import java.util.ArrayList;
      import java.util.Scanner;

      class Actions{

      @SuppressWarnings("unused")
      private int num;
      @SuppressWarnings("unused")
      private int d;
      @SuppressWarnings("unused")
      private char ch;


      public void perform(int num, int d, char ch) {

      this.num=num;
      this.d=d;
      this.ch=ch;

      ArrayList list =new ArrayList();
      String [] numberString = Integer.toString(num).split("");

      list.add(Character.toString((char) (ch-1)));
      list.add(numberString[1]);
      list.add(Integer.toString(d));
      list.add(numberString[3]);
      list.add(Integer.toString(d));
      list.add(Character.toString((char) (ch+1)));
      StringBuilder result= new StringBuilder();
      for (String s: list)
      result.append(s);

      System.out.println("Temp Result : "+result);
      }

      }

      public class Tricky {


      public static void main (String[] args ){

      System.out.println("Please enter Number between 1000 to 9999 :");
      @SuppressWarnings("resource")
      int num = new Scanner(System.in).nextInt();
      System.out.println("Please enter Number between 0 to 9 :");
      @SuppressWarnings("resource")
      int d = new Scanner(System.in).nextInt();
      System.out.println("Please enter character :");
      @SuppressWarnings("resource")
      char ch = new Scanner(System.in).next().charAt(0);

      @SuppressWarnings("rawtypes")
      Actions acs = new Actions();
      acs.perform(num,d,ch);

      }
      }

      Delete
  14. 1. Write a program that takes three double values x0, v0, and t from the user and prints the value x0 +v0t +g t2/2, where g is the constant 9.78033. This value is the displacement in meters after t seconds when an object is thrown straight up from initial position x0 at velocity v0 meters per second.

    Sample run:
    Enter the value of x0, v0 and t: 0 2 2
    The displacement in meters after 2 seconds when an object is thrown straight up from initial position 0 at velocity 2meters per second is: 23.56066

    ReplyDelete
  15. public static void printPyramid(int n) {
    char s = '*';
    for (int i = 1; i <= n/2; i++) {
    for(int j=(i*2-1);j>0;j--){
    System.out.print("* ");
    }
    System.out.println();
    }
    for (int i = n/2+1; i >= 0; i--) {
    for(int j=(i*2-1);j>0;j--){
    System.out.print("* ");
    }
    System.out.println();
    }
    }

    ReplyDelete
  16. Whats the answer for the second one?

    ReplyDelete
  17. Can you post string related coding question? Please send to this mail: vanitha23govindhan@gmail.com

    ReplyDelete
  18. here is my list of programs for practice
    list of Java Program

    Java Program to convert celsius to Farenheit and vice-versa
    area of circle
    perimeter of circle
    are of rectangle
    perimeter of rectangle
    print alphabets
    print multiplication table
    largetst of three integers
    floyd's triangle
    pascal triangle
    add matrices
    transpose matrix
    multiply matrix
    perfect number or not
    find common elements between two arrays
    binary to decimal conversion
    inverse of matrix

    ReplyDelete
  19. exercise for anyone interested?
    1. Write a program that will print the following output

    1
    1 2 1
    1 2 4 2 1
    1 2 4 8 4 2 1
    1 2 4 8 16 8 4 2 1
    1 2 4 8 16 32 18 8 4 2 1




    exercise number 2

    2. Write a class named “Stock” to model a stock. The properties and methods of the class are shown in figure below. The method “changePercent” computes the percentage of the change of the current price vs the previous closing price. Write a client program to test the “Stock” class. In the client program, create a Stock object with the stock symbol SUNW, name Sun Microsystem Inc, previous closing price of 100. Set a new current price randomly and display the price change percentage.

    Stock

    private String symbol
    private String name
    private double previousClosingPrice

    private double currentPrice
    public Stock()
    public Stock(String symbol, String name)

    public String getSymbol()
    public String getName()
    public double getPreviousClosingPrice()
    public double getCurrentPrice()
    public void setSymbol(String symbol)
    public void setName(String name)
    public void setPreviousClosingPrice(double price)
    public void setCurrentPrice(double price)
    public double changePercent()

    ReplyDelete
  20. 1. Write a program that will print the following output
    1
    1 2 1
    1 2 4 2 1
    1 2 4 8 4 2 1
    1 2 4 8 16 8 4 2 1
    1 2 4 8 16 32 18 8 4 2 1

    ReplyDelete
    Replies
    1. import java.util.Scanner;

      public class PracticeDemo {

      public static void getNumber(int number){
      int middle=1;
      String start="1",end="1",output;
      System.out.println(start);
      for(int i=1;i<=number;i++){
      middle=middle*2;
      output=start+" "+middle+" "+end;
      System.out.println(output);
      start=start+" "+middle;
      end=middle+" "+end;
      }


      }


      public static void main(String [] args){
      Scanner sc=new Scanner(System.in);
      System.out.println("Enter the number");
      int x=sc.nextInt();
      getNumber(x);
      sc.close();
      }

      }

      output:
      1
      1 2 1
      1 2 4 2 1
      1 2 4 8 4 2 1
      1 2 4 8 16 8 4 2 1
      1 2 4 8 16 32 16 8 4 2 1
      1 2 4 8 16 32 64 32 16 8 4 2 1
      1 2 4 8 16 32 64 128 64 32 16 8 4 2 1
      1 2 4 8 16 32 64 128 256 128 64 32 16 8 4 2 1
      1 2 4 8 16 32 64 128 256 512 256 128 64 32 16 8 4 2 1
      1 2 4 8 16 32 64 128 256 512 1024 512 256 128 64 32 16 8 4 2 1

      Delete
    2. I would say we should have i<number, instead of i<=number , So that the correct number of rows will print

      Delete
  21. Program#1
    //for beginners
    Question: Write a program to count and print the frequency of word in a sentence(both accepted from the user)
    For example:Inputs//sentence-The lazy lion jumped over the the sharp fence) just kidding!
    word to be searched-the(irrespective of the case)
    The normal way of doing it wud be a little difficult nested loops and compare each letter after finding the match of the first letter. Ill show u my way of doing!!

    import java.io.*;
    class freqWORD
    {
    int count=0;
    public void main()throws IOException
    {
    BufferedReader b=new BufferedReader (new InputStreamReader(System.in));
    System.out.println("Enter a line");
    String line=b.readLine();
    System.out.println("Enter thew word to be searched");
    String word=b.readLine();
    line=" "+line +" " ;
    line=line.replace(word, "0");
    for(int i=0; i<line.length(); i++)
    {
    if(line.charAt(i)=='0'&&line.charAt(i+1)==' '&&line.charAt(i-1)==' ')
    {
    count++;
    }
    }
    System.out.println("the word is repeated " +count +" times");
    System.out.println(line);

    }
    }

    Better?!


    ReplyDelete
    Replies
    1. The easiest way would be below:

      import java.io.*;

      class freqWORD
      {

      public static void main(String[] args)throws IOException
      {
      int count=0;
      BufferedReader b=new BufferedReader (new InputStreamReader(System.in));
      System.out.println("Enter a line");
      String line=b.readLine();
      System.out.println("Enter thew word to be searched");
      String word=b.readLine();

      String lines[] = line.split(" ");

      for( String s: lines){

      if (word.equals(s)){

      count++;
      }
      }

      System.out.println("the word is repeated " +count +" times");
      System.out.println(line);

      }
      }


      Delete
  22. Wap to find the product of first 20 numbers and display in proper format.

    ReplyDelete
  23. I have a ques. How to create application by taking integer to make palidrome coding....

    ReplyDelete
  24. Write a program in Java in DD array to convert all the elements into next prime numbers and display the changed array

    ReplyDelete
    Replies
    1. Answer:

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

      class Solution{

      public int[] strArrayToIntArray(String[] a){
      int[] b = new int[a.length];
      for (int i = 0; i < a.length; i++) {
      b[i] = Integer.parseInt(a[i]);
      }

      return b;
      }

      public int nextPrime(int num) {
      num++;
      for (int i = 2; i <num; i++) {
      if(num%i == 0) {
      num++;
      i=2;
      } else{
      continue;
      }
      }
      return num;
      }

      public int[] nextPrime(int[] data) {

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

      data[i]=nextPrime(data[i]);


      }
      return data;
      }
      }
      public class NextPrime {

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

      System.out.println("Enter the numbers Separated space ");
      BufferedReader br = new BufferedReader (new InputStreamReader(System.in));
      String s =br.readLine();
      String [] question = s.split(" ");
      Solution sol = new Solution();
      int[] data = sol.strArrayToIntArray(question);
      int [] result = sol.nextPrime(data);
      System.out.println("Result is :"+Arrays.toString(result));
      }

      }

      Delete
  25. write a program in java to accept a string from user by command line argument and display the vowel ?

    ReplyDelete
    Replies
    1. Hello @Unknown, you can find the solution of displaying vowel or counting vowel here

      Delete
    2. Solution:

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

      public class vowelCount {

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

      BufferedReader b=new BufferedReader (new InputStreamReader(System.in));
      System.out.println("Enter a line");
      String line=b.readLine();
      String[] solution = line.split("(?!^)");
      System.out.println("Word is :" +line);
      System.out.println("Vowels are :");
      for (String s :solution)
      {
      char c= s.charAt(0);
      switch(c){

      case 'a':
      case 'e':
      case 'i':
      case 'o':
      case 'u':
      System.out.println(c);
      break;
      default:

      }
      }

      }
      }

      Delete
  26. public class Pattern {
    public static void main(String args[]){
    int[][] table = new int[4][4];


    for(int row=0; row<table.length; row++) {
    for(int col=0; col<table[row].length; col++){
    System.out.print(" "+row*col+" ");

    }
    System.out.println();
    }

    }


    }

    output:
    0 0 0 0
    0 1 2 3
    0 2 4 6
    0 3 6 9

    Output needed is:

    0 1 2 3
    1 1 2 3
    2 2 4 6
    3 3 6 9


    what did i do wrong?

    ReplyDelete
  27. try below code...
    for(int row=0; row<table.length; row++) {
    System.out.print(row+" ");

    for(int col=1; col<table[row].length; col++){
    if(row!=0)
    System.out.print(row*col+" ");
    else
    System.out.print(col+" ");


    }
    System.out.println();
    }

    ReplyDelete
    Replies
    1. Sir can you solve this problem? :

      Write a java multiple choice examination program. with 10 questions only (need a specific question). Let the user choose answer and at the end of the program output the total points to the user, output also the number of correct and wrong answer an:

      if the user got 8-10 say "Your in A class"
      f the user got 5-7 say "Your in B class"
      f the user got 0-4 say "Your Fail"


      Note: 1. always ask the user if she/he wants to repeat the exam.
      2. if yes = repeat the exam
      3. if no = exit from the program.

      Delete
    2. Hi, Sorry for the delay. I have added sample basis of two questions in the below program.

      import java.util.*;
      public class JavaOnlineTest {

      public static String questions(){
      Scanner sc=new Scanner(System.in);
      int output=0;
      System.out.println("1)Who is the 45th president of USA?");
      System.out.println("1.Barrack Obama 2.Hillary Clinton 3.Donald Trump 4.George W Bush");
      int answer=sc.nextInt();
      if(answer==3)
      output+=1;
      else
      output+=0;
      System.out.println("2)Who is the 1st Prime Minister of India?");
      System.out.println("1.Subash Chandra Bose 2.Jawahar Lal Nehru 3.Sardar Vallabhai Patel 4.Mahatma Gandhi");
      answer=sc.nextInt();
      if(answer==2)
      output+=1;
      else
      output+=0;
      //proceed for 3rd question here.
      System.out.println("Your result out of 10 is "+output);
      if(output>=0&&output<5){
      System.out.println("You've Failed");
      }else if(output>4 && output<8){
      System.out.println("Your in B Class");
      }else if(output>7 && output<=10){
      System.out.println("Your in A Class");
      }
      System.out.println("Do you want to retake the test");
      System.out.println("Type 'Y' or 'N'");
      String retaking=sc.next().trim();
      return retaking;
      }

      public static void main(String [] args){

      boolean retake;

      String retaking;


      while(true){
      retaking=questions();
      if(retaking.equalsIgnoreCase("Y")){
      retake=true;


      }else if(retaking.equalsIgnoreCase("N")){
      System.out.println("Good Luck!...");
      retake=false;
      retaking="N";
      break;

      }
      }


      }
      }

      Delete
  28. Solve this plss.. fLOW CHART thta accetps a number in kilowatts then display its equivalent number in.Hint:1watt=0.0001 Kilowatt. solve this in java programming

    ReplyDelete
  29. A good one is given the length of a your output media (how wide your paper or screen is) print Pascal's Triangle in Triangle form. Stop when the next line of output will exceed your media width. You can do it two ways ... 1 is figure out how how to space the numbers so they all take the same amount of space (the "center" of the numbers are spaced the same from line to line and from each other; this makes a nice looking triangle, but is harder). 2 an easier version is to center the triangle on the page (left to right) but in each line of numbers the number are separated from each other by only one space You can get more lines in the triangle, but the "sides" are not straight and the relationship between elements gets skewed; however this is much easier.

    ReplyDelete
    Replies
    1. Good questions, can you also post answer, that would be very useful for other readers?

      Delete
  30. Hi! I need help please. I need the code for this exercise please.


    At a certain store they sell blank CD's with the following discounts:

    * 10% for 120 or more
    * 5% for 50 or more
    * 1% for 15 or more
    * no discount for 14 or less

    Write a program that asks for a number of discs bought and outputs the correct discount.

    ReplyDelete
  31. aaaaa
    bbbbb
    AAAAA
    BBBBB

    CAN ANY ONE HELP MET

    ReplyDelete
  32. Write switch case program to show given date(dd/mm/yy) in words format.

    import java.util.Scanner;

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

    String dow;
    String wowby;
    String yowby;

    Double n1,n2,res;
    Scanner scan = new Scanner (System.in);
    System.out.print("Enter Date (dd/mm/yy): ");

    String date = scan.nextLine();
    String dd = date.substring(0,2);
    String mm = date.substring(3,5);
    String yy = date.substring(6,8);

    int d = Integer.valueOf(dd);
    int m = Integer.valueOf(mm);
    int y = Integer.valueOf(yy);

    boolean valid = ((d>=1) && (d<31));
    //||((m>=1) && (m<12));//||((y>=00) && (y<99));

    if(!valid)
    System.out.print("Invalid date");

    else {
    switch (dd)
    {
    case "01":
    System.out.print("First of ");
    switch (mm) {
    case "01":
    System.out.print("January,2020");
    break;

    ReplyDelete
  33. WAP to accept two numbers and find the average OF THE AVERAGES OF THEIR DIGITS

    ReplyDelete
  34. Write a program that reads in from the user an integer (num) between 1000 and 9999. Then it prompts
    the user to enter an integer (d) between 0 and 9 and a character (ch). Your program should replace the
    second and the last digit in num with d and it should display the character that precedes (ch) followed by
    the number after the change and then the character that comes after (ch). Use the division and modulus
    operators to extract the digits from num.

    ReplyDelete
    Replies
    1. bro i did not understand your question properly can you write this again plss, it looks like interesting question....

      Delete

Feel free to comment, ask questions if you have any doubt.