数组未完全打印

Question

import java.util.Scanner;
import java.util.Arrays;

public class Test4 {
    public static void main(String[] args) {
        int randomNumber;
        int[] allNumbers = new int[12];
        Scanner keyboard = new Scanner(System.in);

        for (int i = 1; i <= allNumbers.length; i++) {
            allNumbers[i] = (int) (Math.random() * 999 + 1);
            System.out.print("How many random numbers? ");
            randomNumber = keyboard.nextInt();
            System.out.print("\n" + "Random numbers: ");
            System.out.print(allNumbers[i] + " ");
            {
                System.out.print("\n");
                System.out.print("\n" + "Even numbers: " + (allNumbers[i] % 2 == 0));
                System.out.print("\n" + "Odd numbers: ");
                break;
            }
        }
    }
} 

*update2:增加了Keyboard.nextint的限制。

在我尝试打印赔率和偶数的部分遇到了“字符串文字不是由双引号关闭”的错误。

*update3:修正了上面的错误（由打字造成）。

import java.util.Scanner;
import java.util.Arrays;
public class Test7 {


public static void main(String[] args) {

    Scanner keyboard = new Scanner(System.in);
    System.out.print("How many random numbers?: ");
    int size = keyboard.nextInt();
    System.out.print("\n");
    while (size>12 || size<1);

    int[] randNum = new int[size];

    for(int i = 0 ; i < randNum.length ; i++) 
         randNum[i] = (int)(Math.random() * 999 + 1);
    System.out.println("Random numbers: " + Arrays.toString(randNum).replace("]", "").replace(",", "").replace("[", "") + "\n");


    for(int i = 0 ; i < randNum.length ; i++) 
    if(randNum[i] % 2 == 0) {
     System.out.print("\r" + "Even numbers: ");
     System.out.print(randNum[i] + " ");
    } else {
     System.out.print("\r" + "Odd numbers: ");
     System.out.print(randNum[i] + " ");
    }


}}

Answer 1

Java数组使用基于零的索引。

for(int i = 0; i < allNumbers.length ; i++)

因此，for循环应该如上。否则您可能应该获得ArrayIndexOutOfBoundException。

此外，您在for循环中包含的break语句导致循环不运行一次以上。应该始终使用带有条件的break语句（例如：在if块内）