的System.out在java中

Question

如何進行測試的類下面的System.out在Java中 - 在那裏和我應該怎麼把劇本的System.out

public class DtaPlusMethods { 

    public static void main(String[] args) { 

    } 

    private double a = 1.0; 
    private double b = 2.0; 
    private double c = 3.0; 

    private DtaPlusMethods() 
    {// Empty Constructor 
    } 

    private double Mean() 
    { 
     c = (a + b)/2; 
     return(c); 
    }  

} 

Answer 1

public class DtaPlusMethods { 
    private double a = 1.0; 
    private double b = 2.0; 
    private double c = 3.0; 

    public static void main(String[] args) { 
     DtaPlusMethods thisClass= new DtaPlusMethods(); 
     System.out.println(thisClass.Mean()); 

    } 

    private double Mean() 
    { 
     c = (a + b)/2; 
     return(c); 
    } 
}