[英]Assist me in finding the error: invalid method declaration; return type required
[英]error: invalid method declaration; return type required ERROR While calling a Method
嗨,大家好,我是计算机科学系的新学生,我正在尝试调用一种方法,但我不断遇到此错误。 这是我的问题所在:
calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone);
这是完整的代码(不太长):
import java.util.Scanner;
public class SpeedingTicket
{
public static void main(String[] args)
//Declarations and Instantiations
{
// Input Data
Scanner scan = new Scanner(System.in);
System.out.println("Enter driver's name: ");
String driverName = scan.nextLine();
System.out.println("Enter driver's speed: ");
int speedDriving = scan.nextInt();
System.out.println("Enter speed limit: ");
int speedLimit = scan.nextInt();
scan.nextLine();
System.out.println("Was driver in school zone? ");
String schoolZone = scan.nextLine();
}
// Call calcTicket
calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone);
/** Calculates the cost of a speeding ticket given the speed driven, limit, and if in a school zone.
*/
public static void calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone)
{
// Define constants here
final int INIT_ADDITIVE = 50;
final int NO_MULTIPLIER = 6;
final int YES_MULTIPLIER = 12;
final int MAX_ADDITIVE = 200;
final int EX_THRESH = 30;
// Calculations
int amountOver = (speedDriving - speedLimit);
if (schoolZone.equalsIgnoreCase("yes"))
{
if (amountOver > 0)
{ int fine = amountOver * YES_MULTIPLIER + INIT_ADDITIVE;
System.out.println(driverName +"owes: $" + fine);
}
if (amountOver > EX_THRESH)
{ int fine = amountOver * YES_MULTIPLIER + MAX_ADDITIVE;
System.out.println(driverName +"owes: $" + fine);
}
else
{ int fine = 0;
System.out.println(driverName +"owes: $" + fine);
}
}
if (schoolZone.equalsIgnoreCase("no"))
{
if (amountOver > 0)
{ int fine = amountOver * NO_MULTIPLIER + INIT_ADDITIVE;
System.out.println(driverName +"owes: $" + fine);
}
if (amountOver > EX_THRESH)
{ int fine = amountOver * NO_MULTIPLIER + MAX_ADDITIVE;
System.out.println(driverName +"owes: $" + fine);
}
else
{ int fine = 0;
System.out.println(driverName +"owes: $" + fine);
}
}
}
}
这部分是问题
// Call calcTicket
calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone);
您不能只在这样的类中徘徊代码。 将其放入方法中-我想您希望将其包含在main()中:
public static void main(String[] args)
//Declarations and Instantiations
{
// Input Data
Scanner scan = new Scanner(System.in);
System.out.println("Enter driver's name: ");
String driverName = scan.nextLine();
System.out.println("Enter driver's speed: ");
int speedDriving = scan.nextInt();
System.out.println("Enter speed limit: ");
int speedLimit = scan.nextInt();
scan.nextLine();
System.out.println("Was driver in school zone? ");
String schoolZone = scan.nextLine();
//} --this is not good here!
// Call calcTicket
calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone);
} //put here instead...
您不是在方法(或构造函数)中调用方法。 将回调放置在main
方法中。
public static void main(String[] args)
//Declarations and Instantiations
{
// Input Data
Scanner scan = new Scanner(System.in);
System.out.println("Enter driver's name: ");
String driverName = scan.nextLine();
System.out.println("Enter driver's speed: ");
int speedDriving = scan.nextInt();
System.out.println("Enter speed limit: ");
int speedLimit = scan.nextInt();
scan.nextLine();
System.out.println("Was driver in school zone? ");
String schoolZone = scan.nextLine();
// Call calcTicket
calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone);
}
我不知道,如果格式化得到扭曲,当你砍,你的代码粘贴到这个问题,但显然你需要调用拉calcTicket
进入体内main
。 像这样的东西:
...
System.out.println("Was driver in school zone? ");
String schoolZone = scan.nextLine();
}
// Call calcTicket
calcTicket(String driverName, int speedDriving, int speedLimit, String schoolZone);
像这样:
System.out.println("Was driver in school zone? ");
String schoolZone = scan.nextLine();
// Call calcTicket
calcTicket(driverName, speedDriving, speedLimit, schoolZone);
}
并确保从调用中删除arg类型; 他们是不需要的。
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