42.对象排序

1.不变数组排序

//升序排序  //看小于号返回什么就是什么排序
-(NSArray *)orderedTimeWithArray:(NSArray *)array
{
    NSArray *arr = [array sortedArrayUsingComparator:^NSComparisonResult(Pre_Message *obj1, Pre_Message *obj2) {
        double time1 = [obj1.time doubleValue];
        double time2 = [obj2.time doubleValue];
        if (time1 < time2) {
            return NSOrderedAscending; //升序
        }
        else if (time1 == time2)
        {
            return NSOrderedSame;
        }
        else
        {
            return NSOrderedDescending;
        }
    }];
    return arr;
}


2.可变数组排序

//升序排序  //看小于号返回什么就是什么排序
-(NSMutableArray *)orderedTimeWithArray:(NSMutableArray *)array
{
        [array sortUsingComparator:^NSComparisonResult(Pre_Message *obj1, Pre_Message *obj2) {
        double time1 = [obj1.time doubleValue];
        double time2 = [obj2.time doubleValue];
        if (time1 < time2) {
            return NSOrderedAscending;
        }
        else if (time1 == time2)
        {
            return NSOrderedSame;
        }
        else
        {
            return NSOrderedDescending;
        }
        }];
    return array;
}