排序的NSArray中搜索

在一个已排序的NSArray中搜索某一特定字符串？答案是使用CFArray自带的搜索功能：

 

 

NSMutableArray *sortedArray = [NSMutableArray arrayWithObjects: @"Alice", @"Beth",@"Carol",@"Ellen",nil];

 

//Where is "Beth"?

unsigned index = (unsigned)CFArrayBSearchValues((CFArrayRef)sortedArray,

                                                                                    CFRangeMake(0,CFArrayGetCount((CFArrayRef)sortedArray)),

                                                                                    (CFStringRef)@"Beth",

                                                                                    (CFComparatorFunction)CFStringCompare,

                                                                                    NULL);

if (index < [sortedArray count])

{

         NSLog(@"Beth was found at index %u", index);

} else {

         NSLog(@"Beth was not found (index is beyond the bounds of sortedArray)");

}

 

//Where should we insert "Debra"?

unsigned insertIndex = (unsigned)CFArrayBSearchValues((CFArrayRef)sortedArray,

                                                                                            CFRangeMake(0,CFArrayGetCount((CFArrayRef)sortedArray)),

                                                                                            (CFStringRef)@"Debra",

                                                                                            (CFComparatorFunction)CFStringCompare,

                                                                                            NULL);

[sortedArray insertObject:@"Debra" atIndex:insertIndex];

NSLog([sortedArray description]);