NSString NSBackwardsSearch example ios

Search and Comparison Options - NSBackwardsSearch

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 NSBackwardsSearch]

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 NSBackwardsSearch]

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 NSBackwardsSearch]

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

Example of [NSString NSBackwardsSearch]

NSString *string = @"Here is an example string HELLO ";

NSRange rangeToSearch = NSMakeRange(0, [string length] - 1); // get a range without the space character
NSRange rangeOfSecondToLastSpace = [string rangeOfString:@" " options:NSBackwardsSearch range:rangeToSearch];

NSString *spaceReplacement = @"text that i want";
NSString *result = [string stringByReplacingCharactersInRange:rangeOfSecondToLastSpace withString:spaceRelacement];

Example of [NSString NSBackwardsSearch]

NSString *myString=[NSString stringWithFormat:@"This is my lovely string"];
NSRange range = [myString rangeOfString:@" " options:NSBackwardsSearch range:NSMakeRange(0, 11)];
NSLog(@"range.location: %lu", range.location);
NSString *substring = [myString substringFromIndex:range.location+1];
NSLog(@"substring: '%@'", substring);

Example of [NSString NSBackwardsSearch]

NSRange slashRange = [myString rangeOfString:@"\\" options:NSBackwardsSearch];
NSRange periodRange = [myString rangeOfString:@"." options:NSBackwardsSearch];
NSString *newString = [myString stringByReplacingCharactersInRange:NSMakeRange(slashRange.location, periodRange.location) withString:@"replacement-string-here"];