java array, list 排序

数组排序:

Arrays.sort();

int[] arr = new int[]{1, 5, 3, 2, 4};
Arrays.sort(arr);

输出结果: 1 2 3 4 5 

从大到小排序方式:

Integer[] arr = new Integer[]{1, 5, 3, 2, 4};
Arrays.sort(arr, new Comparator(){
    @Override
    public int compare(Integer o1, Integer o2) {
        return o2-o1;
    }
});

输出结果: 5 4 3 2 1

List排序:

Collections.sort()

List list = new ArrayList<>();
list.addAll(Arrays.asList(new Integer[]{1, 5, 3, 2, 4}));
            
Collections.sort(list);

输出结果: 1, 2, 3, 4, 5

从大到小排序:

List list = new ArrayList<>();
list.addAll(Arrays.asList(new Integer[]{1, 5, 3, 2, 4}));

Collections.sort(list, new Comparator() {
    @Override
    public int compare(Integer o1, Integer o2) {
        return o2-o1;
    }
});

输出结果: 5, 4, 3, 2, 1