java - 如何返回存储在该方法中的 2 个 ArrayList，而不是仅仅将其打印在 void 中？

Question

这个问题已经有答案了:

How to return multiple objects from a Java method? (25 个回答)

已关闭 3 年前。

我只想要我的checkerOddEven()方法是 ArrayList 类型而不是 void，我希望它能够返回存储在每个变量中的两个 Arraylist，这样它就会像 void 方法的当前输出一样打印出来。

这是当前代码的输出: enter image description here

int[] numbers;

public Main(){
    numbers = new int[] {1,2,3,4,5,6,7,8,9,10};
}

public boolean oddEven (int number){

    if(number%2!=0){
        return true;
    }
    return false;

}
public void checkerOddEven (int[] numbers){

    ArrayList<Integer> answerOdd = new ArrayList<Integer>();
    ArrayList<Integer> answerEven = new ArrayList<Integer>();

    for(int number : numbers){
        if(oddEven(number)){
            answerOdd.add(number);
        }
        else answerEven.add(number);
    }

    System.out.println("The Odd numbers are :"+answerOdd);
    System.out.println("The Even numbers are :"+answerEven);

}

public static void main(String[] args) {
    Main main = new Main();

    main.checkerOddEven(main.numbers);
}

Answer 1

我想这就是你想要的？

public static ArrayList<Integer>[] checkerOddEven (int[] numbers){
    ArrayList<Integer> list[]; // I create an Array of ArrayLists
    list = new ArrayList[2]; // I allocate memory for two ArrayLists inside that array. It's important to note that without this, trying to do list[0]=new ArrayList<>(); would have crashed, because there's no list[] yet.
    list[0] = new ArrayList<>();list[1] = new ArrayList<>(); //I create the ArrayList instances by calling their constructor

    for(int number : numbers){
        if(oddEven(number)){
            list[0].add(number);
        }
        else list[1].add(number);
    }

    return list;
}

public static void main(String[] args) {
    Main main = new Main();
    ArrayList<Integer>[] listOfNumbers = (checkerOddEven(main.numbers));
    System.out.print("Odds: "); for(int i=0;i<listOfNumbers[0].size();i++) System.out.print(listOfNumbers[0].get(i)+" ");
    System.out.println(); 
    System.out.print("Even: "); for(int i=0;i<listOfNumbers[1].size();i++) System.out.print(listOfNumbers[1].get(i)+" ");
}