A code block/statement in Java to which the control never reaches and never gets executed during the lifetime of the program is known as unreachable block/statement.public class UnreachableCodeExample {    public String greet() {       System.out.println("This is a greet method ");       return "Hello";       System.out.println("This is an unreachable code ");    }    public static void main(String args[]) {       new UnreachableCodeExample().greet();    } }Dead codeA dead code is an unreachable code, but it doesn’t generate compile time error. But if you execute it in eclipse it gives you a warning.ExampleIn ... Read More

A code block/statement in Java to which the control never reaches and never gets executed during the lifetime of the program is known as unreachable block/statement.Generally, it happens whenever a piece of code hasA return statement before it.An infinite loop before it.Java does not support unreachable code. If you have any such statements, (which are unreachable) Java compiler raises a compile time error.Example1In the following Java program, the class UnreachableCodeExample has a method named greet which returns a String value. After the return statement it has a print statement. Live Demopublic class UnreachableCodeExample {    public String greet() {     ... Read More

A static block is a block of code with a static keyword. In general, these are used to initialize the static members. JVM executes static blocks before the main method at the time of class loading.Example Live Demopublic class MyClass {    static{       System.out.println("Hello this is a static block");    }    public static void main(String args[]){       System.out.println("This is main method");    } }OutputHello this is a static block This is main methodExecuting a static blockJVM first looks for the main method (at least the latest versions) and then, starts executing the program including static ... Read More

The main purpose of constructors in Java is to initialize the instance variables of a class.But, if a class have Static variables you cannot initialize them using the constructors (you can assign values to static variables in constructors but in that scenario, we are just assigning values to static variables). because static variables are loaded into the memory before instantiation (i.e. before constructors are invoked)So, we should initialize static variables from static context. We cannot use static before constructors, Therefore, as an alternation to you can use static blocks to initialize static variables.Static blockA static block is a block of ... Read More

The equals() method compares this string to the specified object. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.Example Live Demopublic class Sample{    public static void main(String []args){       String s1 = "tutorialspoint";       String s2 = "tutorialspoint";       String s3 = new String ("Tutorials Point");       System.out.println(s1.equals(s2));       System.out.println(s2.equals(s3));    } }Outputtrue falseYou can also compare two strings using == operator. But, it compares references of the given variables not ... Read More

Overloading is one of the mechanisms to achieve polymorphism. If a class contains two methods with the same name and different parameters, whenever you call this method the method body will be bound with the method call based on the parameters.ExampleIn the following Java program, the Calculator class has two methods with name addition. The only difference between them is that one contains 3 parameters and the other contains 2 parameters.Here, we can call the addition method by passing two integers or three integers. Based on the number of integer values we pass, the respective method will be executed. Live Demopublic ... Read More

In Java a class is a user defined datatype/blue print in which we declare methods and variables.public class Sample{ }Once you declare a class you need to create an object (instantiate) it. You can create an object using various ways −Using new keywordIn general, an object is created using the new keyword as −Sample obj = new Sample();ExampleIn the following Java we have a class with name sample, which has a method (display). From the main method we are instantiating the Sample class and invoking the display() method. Live Demopublic class Sample{    public void display() {       System.out.println("This ... Read More

The public static void main(String ar[]) method is the entry point of the execution in Java. When we run a .class file JVM searches for the main method and executes the contents of it line by line.You can write the main method in your program without the static modifier, the program gets compiled without compilation errors. But, at the time of execution JVM does not consider this new method (without static) as the entry point of the program.  It searches for the main method which is public, static, with return type void, and a String array as an argument.public static int main(String[] ... Read More

Java provides various access specifiers namely private, public and protected etc...The Private modifier restricts the access of members from outside the class. A class and interface cannot be public.The Public access modifier can be associated with class, method, constructor, interface, etc. public can be accessed from any other class.The protected access modifier can be associated with variables, methods, and constructors, which are declared protected in a superclass can be accessed only by the subclasses in other package or any class within the package of the protected members' class.The default access modifier does not have keyword a variable or method declared ... Read More

Static − If you declare a method, subclass, block, or a variable static it is loaded along with the class.In Java whenever we need to call an (instance) method we should instantiate the class (containing it) and call it. If we need to call a method without instantiation it should be static. Moreover, static methods are loaded into the memory along with the class.In the case of the main method, it is invoked by the JVM directly, so it is not possible to call it by instantiating its class. And, it should be loaded into the memory along with the ... Read More