Abstract classA class which contains 0 or more abstract methods is known as abstract class. If it contains at least one abstract method, it must be declared abstract.If you want to use the concrete method in an abstract class you need to inherit the class, provide implementation to the abstract ... Read More

In general, while reading or writing data to a file, you can only read or, write data from the start of the file. you cannot read/write from random position.The java.io.RandomAccessFile class in Java enables you to read/write data to a random access file.This acts similar to a large array of ... Read More

Once you write a Java program you need to compile it using the javac command, this shows you the compile time errors occurred (if any).Once you resolve them and compile your program success fully, an executable file with the same name as your class name is generated in your current ... Read More

API’s usedThe replaceAll() method of the String class accepts two strings representing a regular expression and a replacement String and replaces the matched values with given String.The java.util class (constructor) accepts a File, InputStream, Path and, String objects, reads all the primitive data types and Strings (from the given source) ... Read More

The split() method of the String class. splits the current string around matches of the given regular expression. The array returned by this method contains each substring of this string that is terminated by another substring that matches the given expression or is terminated by the end of the string.The ... Read More

The java.text package provides a class named SimpleDateFormat which is used to format and parse dates in required manner (local).One of the constructors of this class accepts a String value representing the desired date format and constructors SimpleDateFormat object.The format() method of this class accepts a java.util.Date object and returns ... Read More

Using regular expressionYou can find whether a particular String value contains ASCII characters using the following regular expression −\A\p{ASCII}*\zThe matches() method of the String class accepts a regular expression and verifies whether the current string matches the given expression if so, it returns true, else it returns false.Therefore, Invoke the ... Read More

You can initialize the array variable which is declared inside the class just like any other value, either using constructor or, using the setter method.ExampleIn the following Java example, we are declaring an instance variable of array type and initializing it from the constructor. Live Demopublic class Student {    String ... Read More

There are various methods in Java using which you can parse for words in a string for a specific word. Here we are going to discuss 3 of them.The contains() methodThe contains() method of the String class accepts a sequence of characters value and verifies whether it exists in the ... Read More

We can compare Strings in Java in various ways −Using the comapareTo() method − The compareTo() method compares two strings lexicographically. The comparison is based on the Unicode value of each character in the strings. The character sequence represented by this String object is compared lexicographically to the character sequence ... Read More