Check whether given integer number is prime or not in java (example)
Given an integer, check whether input number is prime or not. A prime number is a natural number greater than 1 […]
Core Java
Program to convert binary number to decimal (java api, iterative & recursive)
Given a binary number, convert binary number to decimal number using java. We discuss various methods to convert binary number
GCD of two numbers Euclidean algorithm in java (iterative/ recursive)
The greatest common divisor (GCD) is the largest natural number that divides two numbers without leaving a remainder. e.g gcd ( 10,15) =
Check given number is palindrome using java (non-recursive/example)
What is palindrome ? A palindrome is a word, number, phrase, or other sequence of characters which reads the same from
Find area & perimeter of a square in java (with example)
What is Square shape ? The square is a fundamental shape in geometry, characterized by several defining properties. It is
Given radius, find area & circumference of circle in java (example)
Given radius of circle, find out the area & circumference of circle in java (with example). Area of circle is PI * radius * radius
Find area & perimeter of rectangle in java (with example)
Given a length and breadth of a rectangle, find the area and perimeter of rectangle. Area of rectangle is length * breadth e.g if
Find area of triangle using base & height in java (example)
Given base & height of triangle, calculate the area of triangle. Area of triangle = 0.5 * base * height. e.g
Find area of triangle (three sides) using hero formula ( java & example)
Given three sides of triangle, find the area of triangle using hero’s formula. Suppose a, b and c are the
Swap two numbers without using third or temporary variable in java
Program to swap two numbers / variable without temporary or third variable in java using XOR , addition / subtraction , multiplication / division methods
Program to check given input number is even or odd in java (example)
What are even & odd numbers ? Given a number in java, check whether number is even or odd The
Find factorial of number in java – recursive & iterative (example)
What is factorial of number? Factorial of a non-negative integer n, denoted by n!. Factorial is the product of all
Reverse number – Leet Code Challenge
Given a input number in java. Reverse input number using iterative or non recursive algorithm. e.g. if input number is
Generate/ print fibonacci series in java – recursive & iterative (example)
What is Fibonacci series? Fibonacci number is obtained by adding two preceding numbers. Fibonacci series is collection of fibonacci numbers. e.g. fibonacci
Java API, recursive & iterative algorithm to reverse string (example)
Given a String in java, reverse the String using standard java classes & recursive/iterative algorithm. e.g. reverse(“Lived”) = “deviL” reverse(“Star”) =
Create or implement FizzBuzz game program in java (with example)
What is Fizz buzz game? FizzBuzz game is very famous interview question. Fizz buzz is a group word game used
try with resources & AutoCloseable java 7 (example & class hierarchy)
The try-with-resources is try statement that used to declare one or more resources. e.g. resources like BufferedReader, Scanner, BufferedWriter can
Catch multiple exceptions before & after java 7 (examples)
What is exception (background)? Exception occurs in an application mostly due to programming mistakes. e.g. NullPointerException occurs, when we try
User defined custom Runtime/Unchecked exception example
What is user defined or custom exception in java? User defined exceptions is concrete class extending exceptions like Exception, RuntimeException
Create custom or user defined unchecked exception in java (example)
Create a user defined exception in java. Create a custom exception, by extending unchecked exceptions. We will create CustomArithmeticException by extending
Encrypt Decrypt message using AES-128 CBC in java (with example)
Given a message, We would like to encrypt & decrypt plain/cipher text using AES CBC algorithm in java. We will
TypeSafe config & HOCON + Read JSON properties in java (example)
Given a java application, We would like to read the property file defined in HOCON (Human-Optimized Config Object Notation.) or
Create runnable jar in java using apache shade plugin (maven/example)
What we will have in this post ? We will create a maven project and add apache shade plug-in. Create runnable
File read write IO operation in java – StringWriter/StringReader (example)
File read write IO operation in java using StringWriter & StringReader. StringWriter write contents as String & StringReader read file as String (example).
Write file in java using PrintWriter (class hierarchy & example)
PrintWriter writes the formatted data to output stream. PrintWriter provides the methods to write int, boolean, char, String, double, float
Read & Write file in java using CharArrayReader & CharArrayWriter (example)
Given the contents, we would like to create or write to file using CharArrayWriter class in java. Read contents from file
Read & write UTF file – BufferReader & BufferWriter (NIO & example)
Given the UTF contents, read & write utf contents using BufferReader & BufferWriter. Use java nio feature to create BufferReader & BufferWriter.
Read /write UTF contents to/ from file in java (BufferReader /BufferWriter /example)
Given UTF contents, read & write utf contents using BufferReader & BufferWriter in java. Write UTF contents to the file
InputStreamReader & OutputStreamWriter – UTF file (example)
Given the UTF contents, read & write utf contents using InputStreamReader & OutputStreamWriter. We have already discussed similar posts: Read & write UTF file
BufferedReader & BufferedWriter (NIO) – Read & write file (java/example)
Read & write file using BufferedReader/BufferedWriter (NIO) with example. BufferWriter writes to character stream & BufferReader, reads character stream.