NSArray of Dates排序

Question

考虑这个数组。它没有密钥，所以我不确定我可以使用NSSortDescriptor。什么是对它们进行排序的最佳方法？

(
    "Thursday, July 30, 2009",
    "Monday, September 07, 2009",
    "Wednesday, September 09, 2009",
    "Friday, August 14, 2009",
    "Saturday, September 05, 2009",
    "Monday, August 10, 2009",
    "Thursday, July 23, 2009",
    "Monday, October 12, 2009",
    "Friday, October 16, 2009",
    "Monday, August 17, 2009",
    "Tuesday, October 13, 2009",
    "Wednesday, September 30, 2009",
    "Sunday, August 16, 2009",
    "Thursday, August 27, 2009",
    "Monday, August 31, 2009",
    "Saturday, August 15, 2009",
    "Thursday, August 06, 2009",
    "Saturday, September 26, 2009",
    "Tuesday, September 29, 2009",
    "Tuesday, September 15, 2009",
    "Tuesday, September 01, 2009"
)

Answer 1

您可以使用 sortedArrayUsingFunction：

这是一些示例代码。

NSInteger dateSort(id s1, id s2, void *context)
{
    NSDateFormatter* format = (NSDateFormatter*)context;
    NSDate* d1 = [format dateFromString:s1];
    NSDate* d2 = [format dateFromString:s2];

    return [d1 compare:d2];
}

...

-(void)someObjectiveCMethod
{
    NSDateFormatter* format = [[[NSDateFormatter alloc] init] autorelease];

    // Find theses format codes here:
    // http://unicode.org/reports/tr35/tr35-6.html#Date_Format_Patterns
    //
    [format setDateFormat:@"EEEE, MMMM dd, yyyy"];

    NSArray* myArray = getMyArray();
    NSArray* sortedArray = [myArray sortedArrayUsingFunction:dateSort context:format];
}

有一个 NSArray中的这些排序方法的数量。值得看看那些熟悉它们的人。

Answer 2

NSArray * unsortedDates = ...;
NSArray * sortedDates = [unsortedDates sortedArrayUsingSelector:@selector(compare:)];