应该如何声明java比较器类以按升序和降序的第二个元素对数组进行排序

Question

int arr[][] = new int[][] {
            {3, 7},
            {1, 2},
            {8, 9},
            {4, 2},
            {5, 3},
            {0,90}
        };

this is my array ,i can sort it ascending or descending order based on there first element using bellow code :

Arrays.sort(arr,(a,b)->Integer.compare(a[0], b[0]));

Now my question is how to do the same thing using second element on the array.

Answer 1

Instead of accessing the first element with index 0 you want to access the second element using index 1 , ie, a[1] and b[1] .

I suggest you should read up on how to use arrays , since this question is not specific to sorting but shows a lack of understanding arrays in general.