如何调用带参数的方法？

Question

好吧，我想做一个程序，既能求二次方程的判别式，又能求根数。到目前为止，我创建了程序来查找判别式，但我无法调用该方法来查找根数。有人可以向我解释这是如何完成的吗？谢谢

 public class quadMethods
 {
     public static void main (String args[])
     {
         new quadMethods ();
     }


     public quadMethods ()
     {
         System.out.println ("The discriminant is: " + discrim (1, 6, 8));
         System.out.println ("The number of roots is: " + numRoots (1, 6, 8));
     }
  public double discrim (double a, double b, double c)
     { //assumes ax^2+bx+c=0
         //returns the discriminant of the quadratic equation
         //b*b-4*a*c
         //replace the return 1
    double discriminant = b*b-4*a*c;    
         return discriminant;
     }


     public int numRoots (double a, double b, double c)
     { //assumes ax^2+bx+c=0
         //returns the number of roots for the quadratic equation
         //call discrim method, make an if to return 0, 1, or 2.
         //replace the return 1
  return 1;
     }
 }

Answer 1

public static void main (String args[])
{
    quadMethods instance = new quadMethods();

    System.out.println(instance.discrim(1.0, 2.0, 3.0));

    int myRoots = instance.numRoots(1.0, 2.0, 3.0);
}

Answer 2

您需要创建一个对象并调用方法

quadMethods qMet =new quadMethods ();
qMet.numRoots (...);

到目前为止你在做什么我只是创建一个对象（但匿名）...

Answer 3

哦对了，我要找的答案是：

public double discrim (double a, double b, double c)
{ 
  return (b*b)-(4*a*c);
}


public int numRoots (double a, double b, double c)
{ 
double d = discrim (a,b,c);
if (d>0)
 return 2;
else if (d<0)
 return 0;
else
 return 1;
}

如何调用带参数的方法？

How to call for a method with parameters?

java

parameters

methods

call