Two-dimensional array sorting (java)

Two-dimensional array sorting requires a comparator

		int [][] ans=new int[intervals.length][2];
        Arrays.sort(intervals, new Comparator<int[]>() {
    
    
            @Override
            public int compare(int[] o1, int[] o2) {
    
    
            	//现在是升序，如果是降序改成o2[0]-o1[0]
                return o1[0]-o2[0];
            }
        });