How to get NSRange(s) for a substring in NSString?

Question

NSString *str = @" My name is Mike, I live in California and I work in Texas. Weather in California is nice but in Texas is too hot...";

How can I loop through this NSString and get NSRange for each occurrence of "California", I want the NSRange because I would like to change it's color in the NSAttributed string.

 NSRange range = NSMakeRange(0,  _stringLength);
 while(range.location != NSNotFound)
 {
    range = [[attString string] rangeOfString: @"California" options:0 range:range];


    if(range.location != NSNotFound)
    {

        range = NSMakeRange(range.location + range.length,  _stringLength - (range.location + range.length));


        [attString addAttribute:NSForegroundColorAttributeName value:_green range:range];
    }
}

score 38 · Accepted Answer · edited Aug 31 '14 at 00:21

Lots of ways of solving this problem - NSScanner was mentioned; rangeOfString:options:range etc. For completeness' sake, I'll mention NSRegularExpression. This also works:

    NSMutableAttributedString *mutableString = nil;
    NSString *sampleText = @"I live in California, blah blah blah California.";
    mutableString = [[NSMutableAttributedString alloc] initWithString:sampleText];

    NSString *pattern = @"(California)";
    NSRegularExpression *expression = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:nil];

    //  enumerate matches
    NSRange range = NSMakeRange(0,[sampleText length]);
    [expression enumerateMatchesInString:sampleText options:0 range:range usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
        NSRange californiaRange = [result rangeAtIndex:0];
        [mutableString addAttribute:NSForegroundColorAttributeName value:[NSColor greenColor] range:californiaRange];
    }];

rangeAtIndex in this example is wrong; it should be accessing 0 not 1 — Alan Zeino, Aug 31 '14 at 00:21

score 20 · Answer 2 · answered Nov 29 '12 at 08:03

20

with

[str rangeOfString:@"California"]

and

[str rangeOfString:@"California" options:YOUR_OPTIONS range:rangeToSearch]

answered Nov 29 '12 at 08:03

tkanzakic

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[str rangeOfString:@"California"] is a good way of finding the range of a substring in a NSString. – iosCurator Dec 16 '16 at 06:39

MANIAK_dobrii · Answer 3 · 2012-11-29T09:15:12.330

0

You may use rangeOfString:options:range: or NSScanner (there are other possibilities like regexps but anyway). It's easier to use first approach updating range, i.e. search for first occurrence and then depending on the result update the search range. When the search range is empty, you've found everything;

edited Nov 29 '12 at 09:15

answered Nov 29 '12 at 08:08

MANIAK_dobrii

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How to get NSRange(s) for a substring in NSString?

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