Java – main() method

Static Members:

• Defining class member with static keyword.
• Static members are:
  • Static main() method
  • Static Block
  • Static Method
  • Static Variable

Static main() method:

• Java program execution starts with main() method.
• JVM invokes the main() method when we run the program.
• We must define main() method as

public static void main(String[] args) Or public static void main(String args[])

Program to display Hello World on Console:

public class Code {             public static void main(String[] args){                         System.out.println(“Hello World”);             } }

Class without main(): We can define class without main() method but we cannot run that class.

public class Code {             void fun(){                         System.out.println(“fun…”);             } }

Runtime Error: No main() method in class Code. Please define main() method

Java Application Structure:

• We define java application in multiple java source files (.java files).
• Source file contains classes.
• Every application has only one execution point(main).
• Main() method belongs to single class from which application execution starts