ArrayList的数组得到索引

Question

我有一个数组的ArrayList，我想改变5的值

 List<int[]> list = new ArrayList<int[]>();
    int[] arr1 = {2,4,6};
    int[] arr2 = {1,3,5};
    list.add(arr1);
    list.add(arr2);

    for (int[] ss : list) 
    {
         for(int sd : ss)
         {  
            //System.out.println(sd);
            if(sd == 5)
            {
             System.out.println("Yes");
             //change 5 to 12
             //list.set(list.indexOf(5), 12);

            }
         }
        System.out.println(Arrays.toString(ss));

    }

[2,4,6] [1,3,5]

我想将5改为12

Answer 1

将您的代码更改为：

 public static void main(String args[]) {

    List<int[]> list = new ArrayList<int[]>();
    int[] arr1 = { 2, 4, 6 };
    int[] arr2 = { 1, 3, 5 };
    list.add(arr1);
    list.add(arr2);

    for (int[] ss : list) {
        for (int i = 0; i < ss.length; i++) {
            // System.out.println(sd);
            if (ss[i] == 5) {                     // if current value is 5
                System.out.println("Yes"); 
                ss[i] = 12;                       // set it to 12 

            }
        }
        System.out.println(Arrays.toString(ss));

    }

}