我正在创建一个程序,在0到9之间生成100个随机整数,并显示每个数字的计数.我正在使用十个整数的数组,计数,以存储0s,1s,...,9s的数量.)
当我编译程序时,我收到错误:
RandomNumbers.java:9:error:类RandomNumbers中的方法generateNumbers不能应用于给定的类型;
generateNumbers();必需:int []
实测值:generateNumbers();
原因:实际和正式的参数列表长度不同
我在main方法中调用方法generateNumbers()和displayCounts()的代码行出现此错误.
public class RandomNumbers {
public static void main(String[] args) {
//declares array for random numbers
int[] numbers = new int [99];
//calls the generateNumbers method
generateNumbers();
//calls the displayCounts method
displayCounts();
}
//*****************************************************************
private static int generateNumbers(int[] numbers){
for(int i = 0; i < 100; i++){
int randomNumber;
randomNumber = (int)(Math.random() *10);
numbers[i] = randomNumber;
return randomNumber;
}
}
//*****************************************************************
private static void displayCounts(int[] numbers){
int[] frequency = new …在编写BookStoreApplication时,它使用Book,Tape和CD类来创建对象.虽然未完成,但应用程序类应创建新的BookStoreItems,即Book,Tape和CD.它们继承自BookStoreItems类.在这个应用程序类中,我不断收到错误:
error: non-static method printMenu() cannot be referenced from a static context
error: non-static method getUserChoice() cannot be referenced from a static context
error: non-static variable input cannot be referenced from a static context
我把它改为静态然后不是静态的,但我继续得到这个错误......
import java.util.Scanner;
public class BookStoreApp2 {
//constants for options
static final int ADD_BOOK = 0;
static final int ADD_TAPE = 1;
static final int ADD_CD = 2;
static final int QUIT = -1;
Scanner input = new Scanner (System.in);
public static void main(String[] args) { …我正在编写一个模拟骰子游戏'Sevens'的Java GUI.
我已经编写了用于创建GUI的主要部分.
我还没有编写程序的实际部分来实际玩游戏.
一切都正确编译,但我收到运行时错误:
Exception in thread "main" java.lang.NullPointerException
at java.awt.Container.addImpl(Unknown Source)
at java.awt.Container.add(Unknown Source)
at SevensGameGUI.,init.(SevensGameGUI.java:88)
at SeventsApplication.main(SevensApplication.java:13)
我不确定导致错误的原因是什么？
以下是SevensGameGUI.java的代码:
//include these import statements in every GUI class
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class SevensGameGUI extends JFrame {
//Instance Variables
// declares an array of integers to store the total score for each player
// allocates memory for 5 players
int[] totalScoreArray = new int[4];
//declares an array of integers to store numbers rolled each time …