Error Main method not found in class Calculate please define the main method as public static void main String args

Question

I need help with the main method  I m getting this error   Error  Main method not found in class Calculate  please define the main method as      public static void main String   args    Here s the code   class Calculate    private double fn  private double sn  private char op   public void setNumber double fnum  double snum       this fn   fnum      this sn   snum    public double getNumber1        return fn    public double getNumber2        return sn    public void setOper char oper       this op   oper    public char getOper        return op    public void getAnswer        double ans      switch  getOper             case  a                 ans   add getNumber1    getNumber2                 ansOutput ans               break           case  b                 ans   sub  getNumber1    getNumber2                 ansOutput ans               break           case  c                 ans   mul  getNumber1    getNumber2                 ansOutput ans               break           case  d                 ans   div  getNumber1    getNumber2                 ansOutput ans               break           default              System out println  --------------------------                System out println  Invalid choice of operator                System out println  --------------------------                        public static double add double x double y           return x   y            public static double sub double x  double y           return x - y            public static double mul double x  double y           return x   y            public static double div double x  double y           return x   y             public static void ansOutput double x           System out println  ----------- -------            System out printf  the answer is   2f n   x           System out println  -------------------

User · Answer

you seem to have not created an main method, which should probably look something like this (i am not sure)

  class RunThis
{
    public static void main(String[] args)
    {

    Calculate answer = new Calculate();
    answer.getNumber1();
    answer.getNumber2();
    answer.setNumber(answer.getNumber1() , answer.getNumber2());
    answer.getOper();
    answer.setOper(answer.getOper());
    answer.getAnswer();
    }
}

the point is you should have created a main method under some class and after compiling you should run the .class file containing main method. In this case the main method is under RunThis i.e RunThis.class.

I am new to java this may or may not be the right answer, correct me if i am wrong

User · Answer

Restart your IDE and everything will be fine

User · Answer

My suggestions      Keep the program modular  Keep the Calculate class in a separate Calculate java file and create a new      class that calls the main method  This would make the code readable  For setting the values in the number  use constructors  Do not use like the methods you have used above like     public void setNumber double fnum  double snum       this fn   fnum      this sn   snum     Constructors exists to initialize the objects This is their job and they are pretty good at it  Getters for members of Calculate class seem in place  But setters are not  Getters and setters serves as one important block in the bridge of efficient programming with java  Put setters for fnum and snum as well In the main class  create a Calculate object using the new operator and the constructor in place  Call the getAnswer   method with the created Calculate object     Rest of the code looks fine to me   Be modular  You could read your program in a much better way   Here is my modular piece of code  Two files   Main java  amp  Calculate java  Calculate java  public class Calculate     private double fn  private double sn  private char op       public double getFn             return fn             public void setFn double fn            this fn   fn             public double getSn             return sn             public void setSn double sn            this sn   sn             public char getOp             return op             public void setOp char op            this op   op               public Calculate double fn  double sn  char op            this fn   fn          this sn   sn          this op   op          public void getAnswer        double ans      switch  getOp             case                   ans   add getFn    getSn                 ansOutput ans               break          case  -                ans   sub  getFn    getSn                 ansOutput ans               break          case                   ans   mul  getFn    getSn                 ansOutput ans               break          case                   ans   div  getFn    getSn                 ansOutput ans               break          default              System out println  --------------------------                System out println  Invalid choice of operator                System out println  --------------------------                        public static double add double x double y           return x   y            public static double sub double x  double y           return x - y            public static double mul double x  double y           return x   y            public static double div double x  double y           return x   y             public static void ansOutput double x           System out println  ----------- -------            System out printf  the answer is   2f n   x           System out println  -------------------              Main java  public class Main       public static void main String args                  Calculate obj   new Calculate 1 2               obj getAnswer

User · Answer

Where you have written the code  public class Main       public static void main String args                  Calculate obj   new Calculate 1 2               obj getAnswer              Here you have to run the class  Main  instead of the class you created at the start of the program  To do so pls go to Run Configuration and search for this class name Main  which is having the main method inside this public static void main String args      And you will get your output

User · Answer

From the docs  In the Java programming language  every application must contain a main method whose signature is   public static void main String   args    The modifiers public and static can be written in either order  public static or static public   but the convention is to use public static as shown above  You can name the argument anything you want  but most programmers choose  quot args quot  or  quot argv quot    As you say   error  missing method body  or declare abstract public static void main String   args     this is what i got after i added it after the class name  You probably haven t declared main with a body  as    quot  would suggest in your error   You need to have main method with a body  which means you need to add   and    public static void main String   args         Add it inside your class definition  Although sometimes error messages are not very clear  most of the time they contain enough information to point to the issue  Worst case  you can search internet for the error message  Also  documentation can be really helpful

[java] Error: Main method not found in class Calculate, please define the main method as: public static void main(String[] args)

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