在NSOrderedAscending和NSOrderedDescending的特定范围内的date

我有这个代码：

NSComparisonResult compareStart = [firstDate compare: dateSelected]; NSComparisonResult compareEnd = [secondDate compare: dateSelected]; if (((compareStart == NSOrderedAscending) || (compareStart == NSOrderedSame)) && (compareEnd == NSOrderedDescending)) 

但它不进入“如果”当firstDate = dateSelected或secondDate = dateSelected …为什么？

Answer 1

你确定当firstDate等于dateSelected时，select的date早于secondDate吗？ 目前你的逻辑是：firstDate <= dateSelected <secondDate。 如果你想要firstDate <= dateSelected <= secondDate，那么你需要实现的代码如下：

 NSComparisonResult compareStart = [firstDate compare: dateSelected]; NSComparisonResult compareEnd = [secondDate compare: dateSelected]; if ( (compareStart == NSOrderedAscending || compareStart == NSOrderedSame) && (compareEnd == NSOrderedDescending || compareEnd == NSOrderedSame)) { // some code } 

更新：

要比较两个NSDate而不依赖于时间，请参阅： 比较两个NSDates并忽略时间分量