NSString NSLiteralSearch example ios

Search and Comparison Options - NSLiteralSearch

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 NSLiteralSearch]

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 NSLiteralSearch]

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 NSLiteralSearch]

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

Example of [NSString NSLiteralSearch]

- (void)findAllLocationsOfString:(NSString *)substring sourceString:(NSString *)source
{
    NSRange searchRange = NSMakeRange(0, [source length]);
    NSRange place = NSMakeRange(0, 0);
    while (searchRange.location < [source length])
    {
        place = [source rangeOfString:substring options:NSLiteralSearch range:searchRange];
        if (place.location != NSNotFound) NSLog(@"found here : %d", place.location);
        searchRange.location = place.location + place.length;
        searchRange.length = [source length] - searchRange.location;
    }
}

Example of [NSString NSLiteralSearch]

[myMutableString replaceOccurrencesOfString:@"target" withString:@"replacement" options: NSLiteralSearch range: NSMakeRange(0, [myMutableString length])];

Example of [NSString NSLiteralSearch]

   NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    NSString *s1 = @"foo";
    NSString *s2 = @"foo";
    NSString *s3 = [[[NSString alloc] initWithString:@"foo"] autorelease];
    NSMutableString *s4 = [NSMutableString stringWithString:@"foobar"];
    [s4 replaceOccurrencesOfString:@"bar"
                        withString:@""
                           options:NSLiteralSearch
                             range:NSMakeRange(0, [s4 length])];

    NSLog(@"s1 = %p\n", s1);
    NSLog(@"s2 = %p\n", s2);
    NSLog(@"s3 = %p\n", s3);
    NSLog(@"s4 = %p\n", s4); // distinct from s1

    NSLog(@"%i", [s1 isEqualToString:s4]); // 1

    [pool release];