Cant call simple method from main method

Question

hi guys, this maybe a stupid question, im a newbie to java programming. Im trying to call the method calculateArea in main method and its not working.
Any ideas?
Thanks.
package project1;
public class makePurchase {
    public int calculateArea(int width, int height){
            int myArea = width * height;
            return myArea;
    public static void main(String[] args){
        int vTestResult = calculateArea(1,3);
        System.out.println("The total is:" +vTestResult);
}

Answer 1

jverd wrote:
mishmash wrote:
Is there a easy way of determining if the method should be static? maybe only if your using a math class and not using the method in any other class?Static means associated with the class as a whole, not with any particular instance. If your method doesn't use or set any state that is part of individual instances, it may be a candidate to be static. Another difference is that static methods cannot be overridden. That is, you can't defer until runtime which class' implementation of a static method to call.
public class Person {
private static int numPersonsCreated;
private String name;
private Date birthdate;
public int calculateAgeInYears () {
// use birthdate to calculate age
public static int getNumPersonsCreated() {
return numPersonsCreated;
}Here, the calc method cannot be static, since it uses the birthdate field that is particular to each Person object created. The number of Person objects created by your program, however, is not associated with any particular Person object, but with the Person class as a whole, so it can be static.Perhaps to expand a bit more...
Highly reusable methods are candidates for static such as utility methods that may be used multiple times.This is true if this methods API remains consistent and does not care a bout the surrounding class. Usually such a method would require all its fields to be provided by parameters or as static members as any instance variables would not make this methods reusable.
in jverd's example you can see that many related classes may be interested in finding out how many people have been created and they may wish to know so at the same time. It certainly makes sense to provide such a method as static as it does not change and most likely never will. More importantly all interested classes now are assured of seeing the exact same method because that is what static is: It exposes the same to all interested parties.
Edited by: Yucca on Oct 19, 2009 6:35 AM