iOS做两个时间判断大小记一下关键字

偶尔会用到，记一下关键字省的以后还要随时去网上找

//比较两个日期的大小
+ (BOOL)compareDate:(NSDate*)stary withDate:(NSDate*)end
{
    NSComparisonResult result = [stary compare: end];
      if (result==NSOrderedSame)
    {
        //相等
        return: NO;
    }else if (result=NSOrderedAscending)
    {
       //结束时间大于开始时间
        return:YES;
    }else if (result=NSOrderedDescending)
    {
        //结束时间小于开始时间
        return:NO;
    }
    return NO;
}

基本上记住NSComparisonResult result = [stary compare: end];就可以了

然后记住

NSOrderedSame
NSOrderedAscending
NSOrderedDescending

还有其他以后补充，临时用到这个就记一下