Everybody talks about how Strings are immutable and how this decision to make Strings immutable has become one of the best things to happen to Java Strings. In this article, we will understand what immutability is and why Java as a programming language decided to make Strings immutable. What is a Mutable Object? From Merriam-Webster…

Iterable and Iterator are both interfaces in Java that sound alike and are often confusing to Java developers. Let’s start by defining the word “iteration”. From Merriam-Webster dictionary, an iteration is the repetition of a sequence of computer instructions a specified number of times or until a condition is met. …

According to Wikipedia, Hypertext Transfer Protocol Secure (HTTPS) is an extension of Hypertext Transfer Protocol (HTTP). It is used for secure communication over a computer network. In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS). …

This is a medium Leetcode 402 question where you are asked to remove k digits from a number to make that number the smallest possible number. See problem description below: The question is quite understandable and straight forward but the issue is with knowing the numbers to remove. At first…

This is a medium Leetcode 543 question. You are given an array of integers of which all elements in the array appear twice except one. The question is to get the one that does not have any duplicate (i.e appeared just once). See problem description below: NOTE: The solution should…

This is an easy Leetcode 733 problem. See problem description below: CONCEPT To get a clearer picture of what the question wants us to do, first, it will be better to break the multidimensional array elements to form a square-like structure e.g …

I must confess this question took me a while as a beginner. This is a medium Leetcode 80 question. This is similar to Leetcode 26 where you are simply asked to remove all duplicates in an array. The tweak in Leetcode 80 is that the highest duplicate a number in…

This is an easy Leetcode problem 367. The question gives a number and you are to write a function to determine if it is a perfect square. See the image below for description. According to wikipedia, a perfect square is the product of a number with itself. in this context…

According to oracle doc, Regular Expressions popularly called Regex are a way to describe a set of strings based on common characteristics shared by each string in the set. They can be used to search, edit, or manipulate text and data. In layman’s term, Regular Expressions are ways that help…