Core java

Most common interview questions are <code>How HashMap works in java</code>, “How get and put method of HashMap work internally”. Here I am trying to explain internal functionality with an easy example. [crayon-60eeb48fbadbe436478285-i/]  is one of the most used Collections in java.Rather than going through theory, we will start with example first, so that you will […]

In this post, we will see how to get current year in Java. Using Date and SimpleDateFormat The Date class was introduced in Java 1.0 and provided different approaches to work with time. The SimpleDateFormat inherits from DateFormat and is mainly used to parse a date to text. You can provide your custom pattern to […]

In this post, we will see how to remove substring from String in java. There are multiple ways to remove substring from String in java. Using String’s replace method to remove substring from String in Java This method belongs to the Java String class and is overloaded to provide two different implementations of the same […]

Java inbuilt LinkedList Java inbuilt LinkedList class uses doubly linked list as internal data structure to store its elements. It is subclass of AbstractList and implements List and Deque interfaces. Insertion and deletion of elements is faster than ArrayList as it interally uses double LinkedList. Print LinkedList using a for loop The most common method […]

In this article, we will see how to print HashMap in java using different method. Print from the HashMap Reference This is the most basic and easiest method to print out HashMap in java. Pass the HashMap reference to the System.out.println, and the HashMap will output the key-value of the elements enclosed in curly brackets. […]

We often have to check if a string contains a substring or not in a case-insensitive manner. There are multiple ways to do so. In this article, we will take a look at these methods for java String contains IgnoreCase checks. Next, we will look at each method in detail. Using String.toLowerCase() One of the […]

If you have worked with Java programs before, you know that all Java programs start by running the main() method(public static void main(String[] args)). The main() method is the entry point. The signature of the main method is fixed, and each portion of the statement has significance. Why is the main method so important? The […]

In this post, we will see how to find and count occurrences of substring in string in java. Using the indexOf() method The indexOf() method in java is a specialized function to find the index of the first occurrence of a substring in a string. This method has 4 overloads. [crayon-60eeb48fbf521811156442/] We will use the […]

💡 Outline You can print double quotes in java by escape double quotes using backslash character(\). [crayon-60eeb48fbff95710111216/] When you print on console using System.out.println, you use double quotes and whatever value inside double quotes is printed. But what if you want to actually print double quotes on console. In this tutorial, we will see different […]

Learn about Question mark operator in java. It is also know as ternary operator.