java - 使用省略号或省略号出了问题

Question

我正在创建一个简单的程序，用于获取姓名、年龄和最喜欢的号码。问题是，当用户选择输入超过 1 个喜爱的号码时，就会出现此异常。

请帮我解决这个在测试类中仍然使用椭圆的问题 --> favnum2 方法。*

测试类

import java.util.Scanner;
public class testing{
public static Scanner input;


public static void main(String[] args){

    boolean choicerepeat=true;
    int favnumoftimes;

    while(choicerepeat==true){
        input = new Scanner(System.in);
        testing2 obj1 = new testing2();
        String name="";
        int age=0;
        favnumoftimes=0;
        double favnum=0, favnumarr[]=new double[999];
        boolean choice1;

        System.out.print("What is your name? ");
        name = input.nextLine();
        System.out.print("What is your age? ");
        age = input.nextInt();

        obj1.message1(name);
        obj1.message2(age);

        System.out.print(name+" do you only have one favorite number? (If yes type 'true' else 'false' - NOTE: lowercase only) ");
        choice1 = input.nextBoolean();

        if(choice1==true)
            favnum1();
        else{
            System.out.println("How many favorite numbers do you have "+name+"? ");
            favnumoftimes = input.nextInt();
            for(int a=0;a<favnumoftimes;a++){
                System.out.print("Enter favorite number "+ (a+1) +": ");
                favnumarr[a]=input.nextDouble();
            }

            for(int a=0;a<favnumarr.length;a++){
                favnum2(favnumoftimes, favnumarr[a]);
            }
        }

        System.out.println();
        System.out.println("Do you want to restart the program? (true(Yes) else false(No)) ");
        choicerepeat = input.nextBoolean();

    }
}

public static void favnum1(){
    System.out.print("Enter favorite number: ");
    double favnumholder1 = input.nextDouble();
    System.out.println("Your favorite number is "+favnumholder1+" ." );
}

public static double favnum2(int favnumoftimesholder,double...favtemphold2){
    System.out.print("Your favorite numbers are ");
    for(int a=0;a<=favnumoftimesholder;a++){
        System.out.print(favtemphold2[a]+", ");
    }
    return 0;
}
}

测试2类

public class testing2{
public static String message1(String nameholder){
    for(int a=0;a<nameholder.length();a++){
        char strholder = nameholder.charAt(a);
        if(Character.isDigit(a)){
            System.out.println("Names don't have numbers... ");
            break;
        }
        else continue;
    }
    System.out.println("\nHi "+nameholder+"! Welcome to my simple program. ");
    return nameholder;
}

public static int message2(int ageholder){
    System.out.println("Your age is "+ageholder+" years old? Oh my goodness. ");
    System.out.println();
    return ageholder;
}
}

Answer 1

问题在于可变参数创建长度等于传递参数数量的新数组。因此 double...favtemphold2 将创建一个新数组 favtemphold2 并且因为您只传递 1 个元素 (favnum2(favnumoftimes, favnumarr[a]);) 该数组的长度为 1。

您可能想要传递更多元素或整个数组，即 favnum2(favnumoftimes, favnumarr);。由于 double... 基本上是 double[] 的语法糖，它们是相等的，并且为 double vararg 传递一个 double 数组将起作用。

对 future 使用可变参数的警告:小心使用Object...，因为数组也是对象。