Resolved Newbie Questions and Hello!

[thorax232]

I'm working on two basic programs, I'm just learning java and getting some errors I don't understand.

The first program uses the "double" for variables in order to print decimals. I know I'm not using it right but this is what I have:

public class Prog4 {
        public static main(String[]) {
        double calc;

                //Formula
                calc = (((9.5*4.5)-(2.5*3))/(45.5-3.5));
                //Print results
                System.out.println(calc);
        }
}

and this is the error I get:

Prog4.java:2: invalid method declaration; return type required
        public static main(String[]) {
                      ^
Prog4.java:2: <identifier> expected
        public static main(String[]) {

I know terrible. The other program I know is written correctly I have others like it, it just prints out some text. But I get this error after successfully compiling and trying to run.

Exception in thread "main" java.lang.NoSuchMethodError: main

I think it's worth mentioning I'm doing this in the VI editor.

[Fou-Lu]

Editor doesn't matter. These errors are essentially caused by the same thing. The first one is complaining that there is no valid return result from the method, and the second is that it is missing the main method (since its not correctly defined). Simply add void as your return type and give your String[] a variable name, and the class will compile and run.

[thorax232]

Originally Posted by Fou-Lu

Editor doesn't matter. These errors are essentially caused by the same thing. The first one is complaining that there is no valid return result from the method, and the second is that it is missing the main method (since its not correctly defined). Simply add void as your return type and give your String[] a variable name, and the class will compile and run.

Derp, I was missing things like "void" and "args" in both programs. Should've caught those myself. Thanks a lot.