我只需要返回一个值，这个值是主类的call方法的节省值。我扩展了子类，但是它不起作用。我也尝试过将子类作为对象导入到父类中，仍然没有成功。
package package1;
import java.util.Scanner;
public class GnX {
FvX fvx = new FvX( );
public static void main(String[] args) {
double price;
double discount;
double savings;
Scanner scan = new Scanner(System.in);
System.out.println("Enter a base price for the discount: ");
price = scan.nextDouble( );
System.out.println("Now, Enter a discount rate: ");
discount = scan.nextDouble( );
displayInfo( );
computeDiscountInfo( );
System.out.println("Special this week on any service over " + price);
System.out.println("Discount of " + discount);
System.out.println("That's a savings of at least $" + savings);
}
public static void displayInfo( ) {
System.out.println("Paradise Guitar Is A Fantastic Place To Reherse");
System.out.println("This Rehersal Room Is Studio Based");
}
}通过单独窗口中的父类继承的类：
package package1;
public class FvX extends GnX {
public FvX( ) {
}
public static double computeDiscountInfo(double price, double discount) {
double savings;
savings = price * discount / 100;
return savings;
}
}
2条答案
按热度按时间sbdsn5lh1#
假设你想使用
computeDiscountInfo，它属于fvx对象，所以应该被称为fvx.computeDiscountInfo(...)现在想想
1.它返回一个双精度值，所以可以执行
double rv = fvx.computeDiscountInfo(...)1.你注意到我写了
(...)，因为这个方法有两个参数double price, double discount，所以你应该使用参数来调用，而不是...，也许是double rv = fvx.computeDiscountInfo(price, discount);vx6bjr1n2#
您要做的是从main方法调用FvX类中的computeDiscountInfo函数。
首先在main方法中创建一个FvX示例，然后使用该fvx对象调用computeDiscountInfo函数。你可以如下所示替换你的main类。