Java Arrays - 哪里也放字符串？ 为什么不起作用？

Question

My program should look like this:

How many random numbers between 0 - 999 do you want? 12 (user input)

Here are the random numbers: 145 538 56 241 954 194 681 42 876 323 2 87

These 7 numbers are even: 538 56 954 194 42 876 2

These 5 numbers are odd: 145 241 681 323 87

I cannot seem too place the String s ( "These 7 numbers are even" and "These 5 numbers are odd" at the right spot in the code. And how do I print the exact number ( 7 and 5 ) of even and odd numbers that are displayed in the String ? The code does not seem to work either way for me. Do you see the problem(s)? Well I hope you can help me figure this out, have been doing this for 12 hours straight now.

Here is my code:

import java.util.Scanner;

public class SlumpadeTal {

    public static void main(String[] args) {

        int evenCounter = 0;
        int oddCounter = 0; 

        Scanner input = new Scanner(System.in);
        System.out.println("How many random numbers between 0 - 999 do you want?");
        int antal = input.nextInt();

        System.out.println("Here are the random numbers:");

        int[] arrayen = new int[antal];
        for (int i = 0; i < arrayen.length; i++) {
            arrayen[i] = (int) (Math.random() * 999 + 1);

            System.out.print(arrayen[i] + " ");
            if ((arrayen[i] % 2) == 0) {
                evenCounter++;
            }
            else {
                oddCounter++;
            }
        }
        int[] evenArray = new int [evenCounter];
        int[] oddArray = new int[oddCounter];
        evenCounter = 0;
        oddCounter = 0;
        for (int i = 0; i < arrayen.length; i++){
            if ((arrayen[i] % 2) == 0) {
                evenArray[evenCounter] = arrayen[i];
                evenCounter++;
            }
            else {
                oddArray[oddCounter] = arrayen[i];
                oddCounter++;
            }       
        }
    }
}

NOTE I cannot use any class such as ArrayList , Vector and so on.

Answer 1

When evenArray & oddArray have values after the last for-loop finished. You just use 2 another loop to print this 2 array.

7 is evenCounter + 1

5 is oddCounter + 1

Ex: String s = "These " + (evenCounter + 1) + "numbers are even: " .... print your array.

Answer 2

Just for your output:

System.out.print("These "+evenCounter+" numbers are even: ");
for (int i = 0; i < evenCounter; i++){
    System.out.print(evenArray[i]+" ");
}
System.out.println();
System.out.print("These "+oddCounter+" numbers are odd: ");
for (int i = 0; i < oddCounter; i++){
    System.out.print(oddArray[i]+" ");
}
System.out.println();

Could work, there are other solutions. For example:

String evStr=new String();
String odStr=new String();

int curNum=0;
for (int i = 0; i < antal; i++) {
    curNum = (int) (Math.random() * 999 + 1);

    System.out.print(curNum + " ");
    if ((curNum % 2) == 0) {
        evStr+=" "+curNum;
        evenCounter++;
    }
    else {
        odStr+=" "+curNum;
        oddCounter++;
    }
}
System.out.println();
System.out.println("These "+evenCounter+" numbers are even: "+evStr);
System.out.println("These "+oddCounter+" numbers are odd: "+odStr);

So the whole second part with even/odd arrays of your code disappears. And there are no arrays at all any more.