Default or no-argument constructor A constructor which does not have any parameter is called default or no-argument constructor. If no constructor is available within the class then java compiler automatically or robotically creates a default constructor on the time of compilation. Syntax: ClassName(){ //Block of statements (Optional) } Why default constructor is used? Default constructor … Read more
Yes, we can run java class without main() method if we use static initalizer and having System.exit(0); statement at the end. Program will compile and execute. public class Test{ static{ System.out.println("Hello Test"); System.exit(0); }public class Test{ static{ System.out.println("Hello Test"); System.exit(0); } But it can be done only upto JAVA 6 version. From Java-7 version the … Read more
As we discussed in previous question that we can overload main method. We can change the return type for main method but java compiler will refuse to acknowledge it as entry point for our application. Example public class Main { public static String main(String[] args) { System.out.println("main method with "); return "w3schools.com"; } }public class … Read more
JVM invokes main method even before the instantiation of the class. As non-static members or methods cannot be called with the class name directly so main() method should be declared as static. Java interview questions on main method Can we overload main() method in java? Can we declare main() method as private or protected or … Read more
No, JVM invokes main method even before the instantiation of the class. As non-static members or methods cannot be called with the class name directly so main() method should be declared as static. Example public class Main { public void main(String[] args) { System.out.println("Non static main method."); } }public class Main { public void main(String[] … Read more
No, we declare main() method as private or protected or with no access modifier because if we declare so, main() will not be accessible to JVM. Class will compile successfully but will get run time error as no main method found. Example: public class Main { protected static void main(String[] args) { System.out.println("Protected main method."); … Read more
Yes, we can overload main() method. A Java class can have any number of main() methods. But it should have one main() method with signature as “public static void main(String[] args)” to run. If not class will compile but not run. Example /** * This class is used for main method overloading. * @author w3schools … Read more
Yes, save your java file by .java then compile it by javac .java and run by java yourclassname class Test { public static void main(String args[]) { System.out.println("Hello World"); } } class Test { public static void main(String args[]) { System.out.println("Hello World"); } } to compile: javac .java to execute: java Test
ClassLoader in Java is a class that is used to load class files in Java. Java code is compiled into the class file by javac compiler and JVM executes Java program, by executing byte codes written in the class file. ClassLoader is responsible for loading class files from file system, network or any other source. … Read more
To call the main method present in Java code, the JVM(Java Virtual Machine) is used which is a part of the JRE(Java Runtime Environment) and acts as a run-time engine to run Java applications. Because of JVM, a Java code can be developed on one system and can be expected to run on any other … Read more