Question

    class EX6
    {
        private int value;

        public static void main(String [] args)
        {
            Scanner input = new Scanner(System.in);
            System.out.println("Enter some numbers (all on one line, separated by spaces):");
            String line = input.nextLine();
            String[] numbers = line.split(" +");
            ArrayList<Integer> a = new ArrayList<Integer>();

            for(int i=0; i<numbers.length; i++)
                a.add(new Integer(numbers[i]));
            System.out.println("The numbers are stored in an ArrayList");
            System.out.println("The ArrayList is "+a);

            EX6 ex = new EX6();
            ex.value = Integer.parseInt(JOptionPane.showInputDialog("Enter a number"));

            System.out.println(removeNumber(a,ex));
        }

        public static <T> ArrayList<T> removeNumber(ArrayList<T> a, EX6 e)
        // Adds n after every occurrence of m in a, constructively.
        {
            ArrayList<T> b = new ArrayList<T>();
            for(int i=0; i<a.size(); i++)
            {
                if(a.get(i) == e)
                {
                    a.remove(i);
                }
            }
            return a;

如果我在[5,12 ,4, 16,4]中输入值ArrayList，并在4中输入JOptionPane，我想删除所有4'列表中的。

我如何将ex.value传递给方法removeNumber（）???

Answer 1

您可以重复使用ArrayList.remove（Object）

ArrayList al = ...; int elementToRemove = ...; boolean found; do { found = al.remove((Integer)elementToRemove); } while (found);

Answer 2

你可以尝试这个，只需通过它定义迭代器和迭代器，找到你要删除的匹配元素，然后从迭代器中删除。它将删除Arraylist中的元素，因为Iterator指的是Arraylist。

public static <T> ArrayList<T> removeNumber(ArrayList<T> a, EX6 e)
{
       Iterator i = a.iterator();
       while(i.hasNext())
       {
           if(i.next().equals((Integer)e.value))
           {
            i.remove();
           }
       }
       return a;
}

试图从arraylist中删除特定对象

2 个答案: