NSString NSStringEnumerationByWords example ios

String Enumeration Options - NSStringEnumerationByWords

Constants to specify kinds of substrings and styles of enumeration.

typedef NSUInteger NSStringEnumerationOptions;
enum {
NSStringEnumerationByLines = 0,
NSStringEnumerationByParagraphs = 1,
NSStringEnumerationByComposedCharacterSequences = 2,
NSStringEnumerationByWords = 3,
NSStringEnumerationBySentences = 4,
NSStringEnumerationReverse = 1UL << 8,
NSStringEnumerationSubstringNotRequired = 1UL << 9,
NSStringEnumerationLocalized = 1UL << 10
};

Constants

NSStringEnumerationByLines

Enumerates by lines. Equivalent to lineRangeForRange:.

NSStringEnumerationByParagraphs

Enumerates by paragraphs. Equivalent to paragraphRangeForRange:.

NSStringEnumerationByComposedCharacterSequences

Enumerates by composed character sequences. Equivalent torangeOfComposedCharacterSequencesForRange:.

NSStringEnumerationByWords

Enumerates by words.

NSStringEnumerationBySentences

Enumerates by sentences.

[NSString NSStringEnumerationByWords]

NSStringEnumerationReverse

Causes enumeration to occur from the end of the specified range to the start.

NSStringEnumerationSubstringNotRequired

A way to indicate that the block does not need substring, in which case nil will be passed. This is simply a performance shortcut.

NSStringEnumerationLocalized

Causes the enumeration to occur using user's default locale. This does not make a difference in line, paragraph, or composed character sequence enumeration, but it may for words or sentences.

Discussion of [NSString NSStringEnumerationByWords]

These options are used with theenumerateSubstringsInRange:options:usingBlock: method. Pass in oneNSStringEnumerationBy... option and combine with any of the remaining enumeration style constants using the C bitwise OR operator.

Example of [NSString NSStringEnumerationByWords]

[strWord enumerateSubstringsInRange:NSMakeRange(0, [strWord length])
                            options:NSStringEnumerationByWords
                         usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop){
    // ...
}];

Example of [NSString NSStringEnumerationByWords]

__block NSInteger length = 0;
[string enumerateSubstringsInRange:range
                           options:NSStringEnumerationByWords
                        usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
    length++;
}];

Example of [NSString NSStringEnumerationByWords]

#warning I haven't tested this thoroughly
NSString *string = @"Hello";
__block NSString *firstCharacterSequence = nil;
[string enumerateSubstringsInRange:NSMakeRange(0, string.length) 
                           options:NSStringEnumerationByWords 
                        usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop){
                            firstCharacterSequence = substring;
                            *stop = YES;
                        }];
NSLog(@"%@",firstCharacterSequence);