If you have just started learning basics of Java programming language or familiar
with programming in either C or C++ then these Java programming questions and exercises for
you. It doesn't focus on particular part of Java but these coding exercises
will switch you in programming mode.These are also great way 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 common Java API. You may also
find these Java programming questions in most of Java courses taught in school,
colleges and various Java training courses. Even I have started learning Java
by doing these exercises multiple times with different ways. They are
interesting, gives feeling of accomplishment if you complete it. These Java programs
looks simple but they are still tricky for novice Java programmers. Try to
solve these coding exercises by yourself but if you stuck you can check
relevant links or of-course use google to get more insight on them. You can also
see here more Java programming
questions and exercises.

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__Java Programing Questions exercises for beginners to
practices__

Here is my list of 10 Java programming questions or Java programs which can help any beginner to get
started in 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 solution 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 completely divisible by two. For example number 4 is even number
because when you do 4/2 , remainder is 0 which means 4 is completely divisible
by 2. On the other hand 5 is odd number because 5/2 will result in remainder as
1. See here to find how to check even and odd number 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 algorithm to find prime numbers e.g. instead of dividing till number,
division upto square root of number may be enough. Start from simplest one and
than try to solve this problem with couple of different ways. Here is one way
to check prime numbers in Java

**3. Write Java program to check if a number is palindrome in Java?**( 121 is palindrome, 321 is not)

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

**4. How to find if a number is 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 e.g. using arithmetic operator or by using bit
shift operator.

**5. Write program to sort an integer array without using API methods?**

Sorting questions are one of the integral part of programming questions. There are many sorting algorithm out there to sort any array in Java e.g.
Bubble sort, Insertion sort, Selection sort or quick sort. Implementing sorting
algorithm itself a good programming exercise in Java. By the way here is one
way to sort an integer array with Bubble sort
algorithm in Java.

**6. Write Java program to check if a number is Armstrong number or not?**(input 153 output true, 123 output false)

An Armstrong number of 3 digit is a number for which sum of cube of its
digits are equal to number e.g. 371 is an Armstrong number because 3*3*3
+ 7*7*7 + 1*1*1 = 371). See here for sample Java program to check if a number is 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 than
look to implement a recursive solution. Here is one way to reverse String in Java without using
StringBuffer.

**8. Write a program in Java to print Fibonacci series up to given number? Write both iterative and recursive version.**

Fibonacci series a popular number series and very popular programming question in Java, in which number is equal to sum
of previous two numbers, starting from third. Fibonacci series is also a good
recursion exercise and often asked in Interviews as well. Try doing this exercise by using both Iteration e.g. loops and recursion. For help see How to print Fibonacci series in Java
using recursion.

**9. Write a Java program to calculate factorial of an integer number ? Both iterative and recursive solution.**

Calculating Factorial is also a classic recursion exercise in
programming. Since factorial is a recursive function, recursion becomes natural
choice to solve this problem. You just need to remember 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 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())

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These were some programming questions and exercises for beginners learning 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 programming and help converting
logic to code.

Other

**Java programming tutorials**for beginners
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.

ReplyDeleteTo 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.

ReplyDeleteA 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.

ReplyDeleteI 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.

ReplyDelete1) 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.

can you show the output of 1st programme

DeleteAdmin 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....)

ReplyDeleteExercise 10 for anyone interested, simple version.

ReplyDeletepublic 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();

}

}

}

}

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*****

******

*******

********

*********

**********

**********

*********

********

*******

******

*****

****

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**

*

1

333

55555

7777777

999999999

999999999

7777777

55555

333

1

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

ReplyDeleteimport java.util.Scanner;

Deletepublic 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");

}

}

}

public class ArmstrongNo {

Deletepublic 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");

}

}}

My solution for part 4, im a beginner.

ReplyDeleteimport 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");

}

}

}

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.

Deleteimport 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");

}

}

Too easy programs...........

ReplyDeleteA Dynamic Solution:

ReplyDeletepublic 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;

}

}

}

}

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.

ReplyDelete3. 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.

ReplyDeleteSample 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

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.

ReplyDeleteSample 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.

import java.io.*;

Deleteimport 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));

}

}

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.

ReplyDeleteSample 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

public static void printPyramid(int n) {

ReplyDeletechar 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();

}

}