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

如何在一个已排序的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 = [NSMutableArrayarrayWithObjects:@"Alice",@"Beth",@"Carol",@"Ellen",nil];

//Where is "Beth"?

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

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

(CFStringRef)@"Beth",

(CFComparatorFunction)CFStringCompare,

NULL);

if(index < [sortedArraycount])

{

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"?

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

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

(CFStringRef)@"Debra",

(CFComparatorFunction)CFStringCompare,

NULL);

[sortedArrayinsertObject:@"Debra"atIndex:insertIndex];

NSLog([sortedArraydescription]);

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

//Where is "Beth"?

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

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

(CFStringRef)@"Beth",

(CFComparatorFunction)CFStringCompare,

NULL);

if(index < [sortedArraycount])

{

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"?

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

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

(CFStringRef)@"Debra",

(CFComparatorFunction)CFStringCompare,

NULL);

[sortedArrayinsertObject:@"Debra"atIndex:insertIndex];

NSLog([sortedArraydescription]);