NSString NSNumericSearch example ios

Search and Comparison Options - NSNumericSearch

These values represent the options available to many of the string classes’ search and comparison methods.

enum {
   NSCaseInsensitiveSearch = 1,
   NSLiteralSearch = 2,
   NSBackwardsSearch = 4,
   NSAnchoredSearch = 8,
   NSNumericSearch = 64,
   NSDiacriticInsensitiveSearch = 128,
   NSWidthInsensitiveSearch = 256,
   NSForcedOrderingSearch = 512,
   NSRegularExpressionSearch = 1024
};

Constants

NSCaseInsensitiveSearch

A case-insensitive search.

NSLiteralSearch

Exact character-by-character equivalence.

NSBackwardsSearch

Search from end of source string.[NSString NSNumericSearch]

NSAnchoredSearch

Search is limited to start (or end, if NSBackwardsSearch) of source string.

NSNumericSearch

Numbers within strings are compared using numeric value, that is, Name2.txt <Name7.txt < Name25.txt.

This option only applies to compare methods, not find.

NSDiacriticInsensitiveSearch

Search ignores diacritic marks.[NSString NSNumericSearch]

For example, ‘ö’ is equal to ‘o’.

NSWidthInsensitiveSearch

Search ignores width differences in characters that have full-width and half-width forms, as occurs in East Asian character sets.

For example, with this option, the full-width Latin small letter 'a' (Unicode code point U+FF41) is equal to the basic Latin small letter 'a' (Unicode code point U+0061).

NSForcedOrderingSearch

Comparisons are forced to return either NSOrderedAscending orNSOrderedDescending if the strings are equivalent but not strictly equal.

This option gives stability when sorting. For example, “aaa” is greater than "AAA” if NSCaseInsensitiveSearch is specified.

NSRegularExpressionSearch

The search string is treated as an ICU-compatible regular expression. If set, no other options can apply except NSCaseInsensitiveSearch and NSAnchoredSearch. You can use this option only with the rangeOfString:...methods and stringByReplacingOccurrencesOfString:withString:options:range:.

Discussion of [NSString NSNumericSearch]

See “Searching, Comparing, and Sorting Strings” for details on the effects of these options.

Example of [NSString NSNumericSearch]

NSArray * strings = [NSArray arrayWithObjects: @"Seinfeld (Season 6)", @"Batman", @"Seinfeld (Season 5)", @"Zoolander", nil];
NSArray * sorted1 = [strings sortedArrayUsingComparator: ^(id first, id second) {
                        return [(NSString *)first compare:(NSString *)second options: NSNumericSearch];
                    }];
NSArray * sorted2 = [strings sortedArrayUsingComparator: ^(id first, id second) {
    return - [(NSString *)first compare:(NSString *)second options: NSNumericSearch];
    // or (to be more clear, but less efficient)
    // return -1 * [(NSString *)first compare:(NSString *)second options: NSNumericSearch];
}];

NSLog(@"starting: %@", strings );
NSLog(@"sort1: %@", sorted1 );
NSLog(@"sort2: %@", sorted2 );

Example of [NSString NSNumericSearch]

NSArray *sortedArray = [array sortedArrayUsingComparator: ^(id firstString, id secondString) {
  return [(NSString *)firstString compare:(NSString *)secondString  options:NSNumericSearch];
}];

  NSLog(@"========= %@================= ", sortedArray);

Example of [NSString NSNumericSearch]

@interface NSString(NumericCompare)

-(NSComparisionResult) compareNumerically: (NSString*) anotherString;

@end

@implementation NSString(NumericCompare)

-(NSComparisionResult) compareNumerically: (NSString*) anotherString
{
    return [self compare: anotherString options: NSNumericSearch];
}