10 Programming questions and exercises for Java Programmers (original) (raw)

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 alsosee 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 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.

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())

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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.

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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.