Core Java interview

Learn about how to implement Rock Paper Scissors game in java.

I have been posting data structure and coding interview questions on various topics such as Array, Queue, Stack, Binary tree, LinkedList, String, Number, ArrayList, etc. So I am consolidating a list of java coding interview questions to create an index post. I will keep adding links to this post whenever I will add new java […]

In this article, we are going to find first and last digit of a number. To find first and last digit of any number, we can have several ways like using modulo operator or pow() and log() methods of Math class etc. Let’s see some examples. Before moving to example, let’s first create an algorithm […]

In this article, we are going to learn to find Happy Number using Java. Let’s first understand, what is Happy Number? What is a Happy Number? A number which leaves 1 as a result after a sequence of steps and in each step number is replaced by the sum of squares of its digit. For […]

In this article, we are going to find whether a number is perfect or not using Java. A number is called a perfect number if the sum of its divisors is equal to the number. The sum of divisors excludes the number. There may be several approaches to find the perfect number. For example: 28 […]

In this article, we are going to learn to find Magic Number using Java. Let’s first understand, what is Magic Number? What is a Magic Number? A number which leaves 1 as a result after a sequence of steps and in each step number is replaced by the sum of its digits. For example, if […]

In this article, we will implement Number guessing game in java. The number guessing game is based on a concept where player guesses a number between a range. If player guesses the exact number then player wins else player looses the game. Since this game provides limited attempts, so, player must guess the number with […]

In this post, we will see about Java 8 PriorityQueue. When the objects are supposed to be processed on the basis of their priority, in that scenario we use PriorityQueue. It’s a special type of queue (also, unbound queues) where the elements can be ordered either as per their natural ordering or based on a […]

In this post, we will see how to convert decimal to binary in java. There are lot of ways to convert decimal to binary in java.Let’s explore them one by one. Using Integer.toBinaryString() method You can simply use inbuilt Integer.toBinaryString() method to convert a decimal [crayon-6869aa0d3fdef553660934/] Output: Binary representation of 12 : 1100 Binary representation […]