Overview In this Blog we will find answer for following questions What is Primitive Type. What is Wrapper Class. Convert one into another. Ideal scenario to use Primitive vs Wrapper. Primitive Type Primitive types directly contain values. Java defines many primitive type variables. We will see mainly int vs Integer. Read more…
Overview We will find answers for the following questions What is String pool? How does memory allocation work for String? Why is String immutable. String pool String pool is a special storage area in Java heap. When a string is created and if the string already exists in the pool, Read more…
Based on my previous posts related to Comparator and Comparable let’s see the difference. Comparable Comparator Should be used when sorting with one element only Should be used when sorting with multiple elements Need to implement compareTo(Obj ob) Need to implement compare(Obj e1, Obj e2) Found in java.lang package Found in java.util package Actual Read more…
In my previous post, we saw Comparable and it’s implementation. Java provides another way to compare objects. Instead of implementing the comparable interface, we can implement the Comparator interface. The main difference between these two interfaces is that the comparable interface defines one method compareTo(), which takes one parameter. The Comparator interface defines Read more…
How do we sort in Java? We can go the traditional way by implementing Bubble Sort or Merge Sort etc We can use Java APIs In this post, we will focus on Sorting using Java APIs Sort List of Integer Given an Integer List say [7, 4, 2, 9, 5, Read more…
Let’s start with 2 basic rules to follow Convert Date (java.util.Date) into String => format Convert String into Date => parse I have used SimpleDateFormat which extends DateFormat of java.text package. A date can be in various formats. Here are few Let’s see an Example Note: Suppose we need to convert String Date format Read more…
An exception is an abnormal condition that arises in a code sequence at run time. Java exception handling is managed via five keywords: try, catch, throw, throws, and finally. Workflow Program statements that you want to monitor for exceptions are contained within a try block. If an exception occurs within the Read more…
Let’s start with a little program in java to print a line “Hello World” Line 1 public : One of Access Modifiers. It makes this piece of code visible to the world. class : A class is a blueprint from which individual objects are created. HelloWorld : Name of the class Line Read more…