Collections.sort(List<T> list, Comparator<? super T> c)
ArrayList<Integer> arrayList = new ArrayList<Integer>();
arrayList.add(-1);
arrayList.add(3);
arrayList.add(3);
arrayList.add(-5);
arrayList.add(7);
arrayList.add(4);
arrayList.add(-9);
arrayList.add(-7);
System.out.println("原始数组:");
System.out.println(arrayList);
// void reverse(List list):反转
Collections.reverse(arrayList);
System.out.println("Collections.reverse(arrayList):");
System.out.println(arrayList);
// void sort(List list),按自然排序的升序排序
Collections.sort(arrayList);
System.out.println("Collections.sort(arrayList):");
System.out.println(arrayList);
// 定制排序的用法
Collections.sort(arrayList, new Comparator<Integer>() {
@Override
public int compare(Integer o1, Integer o2) {
return o2.compareTo(o1);
}
});
System.out.println("定制排序后:");
System.out.println(arrayList);
Output:
原始数组:
[-1, 3, 3, -5, 7, 4, -9, -7]
Collections.reverse(arrayList):
[-7, -9, 4, 7, -5, 3, 3, -1]
Collections.sort(arrayList):
[-9, -7, -5, -1, 3, 3, 4, 7]
定制排序后:
[7, 4, 3, 3, -1, -5, -7, -9]