How do i find range of locations of a word in a sentence in objective c?-CodePudding

How do i find range of locations of a specific word in a sentence in objective c?

Lets say i have the following NSString

NSString *stringOfHashTags = "mr#hello Mr.#hello"

I am using

NSString word=@"hello";
    NSRange termsRange = [stringOfHashTags rangeOfString:[word substringFromIndex:[word rangeOfString:@"#"].location]];

to find the location of a word that starts with # but if the word exists two or more times in the sentence it only returns the first location. Any help appreciated.

CodePudding user response：

You can use enumerateSubstringsInRange (searching and reading documentation is always the starting point).

Simple example:

NSString *aString = @"mr#hello Mr.#hello";
NSString *word = @"hello";
[aString enumerateSubstringsInRange:NSMakeRange(0, [aString length])
                            options:NSStringEnumerationByWords | NSStringEnumerationLocalized
                         usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop){
    if ([substring rangeOfString:word options:NSCaseInsensitiveSearch].location != NSNotFound) {
        /* do whatever */;
        NSLog(@"found at: %@ / %@", [NSValue valueWithRange:substringRange], [NSValue valueWithRange:enclosingRange]);
    }
}];

debug console output:

proj[64417:6900139] found at: NSRange: {3, 5} / NSRange: {3, 6}
proj[64417:6900139] found at: NSRange: {13, 5} / NSRange: {13, 5}

Edit

If you want to find all words that begin with # in a string such as:

"this #is a #test of #88 including embedded #tags such as Mr.#tags. #Is that #what you're looking #for?"

as opposed to finding multiple occurrences of a word (as in your question), you likely want to use Regular Expressions.

Another quick, simple example:

NSString *searchedString = @"this #is a #test of #88 including embedded #tags such as Mr.#tags. #Is that #what you're looking #for?";
NSRange searchedRange = NSMakeRange(0, [searchedString length]);

// searching for any Word that begins with #
NSString *pattern = @"\\#\\w ";
NSError  *error = nil;

NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern: pattern options:0 error:&error];
if (error) {
    NSLog(@"Could not create regex!!!");
    return;
}

NSArray *matches = [regex matchesInString:searchedString options:0 range: searchedRange];
for (NSTextCheckingResult *match in matches) {
    NSString *matchText = [searchedString substringWithRange:[match range]];
    NSLog(@"match: %@", matchText);
}

debug console output:

proj[66898:6935236] match: #is
proj[66898:6935236] match: #test
proj[66898:6935236] match: #88
proj[66898:6935236] match: #tags
proj[66898:6935236] match: #tags
proj[66898:6935236] match: #Is
proj[66898:6935236] match: #what
proj[66898:6935236] match: #for

Edit 2

Your second comment really should be a new post, as it's an entirely different question (about RegEx syntax).

But, to get you on your way...

NSString *searchedString = @"These #tags, with #various& #excluded! #chars. And #other@ formats #88 including #emo