Core java

The FileWriter class of java.io package makes writing to files in Java as easy as A-B-C. The FileWriter class writes to files as a stream of characters instead of bytes(as in FileOutputStream). Like its input-oriented counterpart FileReader, the FileWriter class is intended for writing “text” based files one character at a time. Let us look […]

In this tutorial, we will see java program to find permutation and combination. Permutation is represented as nPr and Combination is represented as nCr.It is simple program which involves factorial of the numbers. Here is formula to find permutation and combination (nCr nPr). nPr = factorial(n) / factorial(n-r) nCr = factorial(n)/(factorial(n-r) * factorial(r)) [crayon-67427e7f282f9258138845/] Output: Enter […]

Binding in Java refers to the process of associating a method or function body with a method or function call by the Java Compiler. In simpler words, when a function is called by the Java compiler the task of correctly locating the method for the respective function is binding. Depending on when the compiler is […]

In this post, we will see how to call getters and setters using reflection in java. We have already seen how to invoke method using reflection in java. There are two ways to invoke getter and setter using reflection in java. Using PropertyDescriptor You can use PropertyDescriptor to call getters and setters using reflection. Getter: […]

In this post, we will see how to add elements to the array. Using Apache’s common lang library You can use varargs add method to add elements to array dynamically. Here are the few add overloaded methods provided by ArrayUtils class If you want to add more than one element, you can use ArrayUtils’s addAll […]

In this post, we will see why wait(), notify() And notifyAll() methods are in Object Class And Not in Thread Class. This is one of the most asked java multithreading interview questions. You might know that wait(), notify() And notifyAll() Methods are in Object class and do you know the reason for the same? Let’s […]

In this post, we will see how to sort HashSet in java. HashSet is a collection which does not store elements in any order. You might come across a situation where you need to sort HashSet. There can be many ways to sort HashSet, we will see two methods here. Using TreeSet You can use […]

In this post, we will see about the difference between equals and == in java. This is most asked java interview question for fresher or 2-year experienced java developer and it might be confusing sometimes. Let’s try to understand each quickly. Equality operator “==” Equality operator can be used to compare primitives but when you […]

In this post, we will learn java array to set conversion. There are many ways to convert array to set. 1. Using Java 8’s Stream If you are using Java 8, I would recommend using Java 8 Stream. [crayon-67427e7f28d49307503463/] Output [John, Martin, Mary] 2. Using HashSet constructor() We can directly call HashSet‘s constructor for java […]