How to strip part of an NSString after the first instance of a character?

Question

I would like to strip part of an NSString.

in the following string I would like to just grab the digits before the "/sampletext1/sampletext2/sampletext3"

1464/sampletext1/sampletext2/sampletext3

I have already stripped out the web address before the digits, but can't figure out the rest. Sometimes the digits could be 3 or 4 or 5 digits long.

thanks

Are you dealing with a URL? If so, you can convert to an NSURL and extract the various parts: path, host, port, query string, etc. — Brian Nickel, Sep 17 '13 at 21:17
Otherwise, regular expressions are a good approach `@"^\\d+"`. — Brian Nickel, Sep 17 '13 at 21:18
I ended up using: http://stackoverflow.com/questions/3692947/get-parts-of-a-nsurl-in-objective-c — user2588945, Sep 17 '13 at 22:34

rmaddy · Answer 1 · 2013-09-17T21:24:15.467

6

Get the index of the first / character then get the substring up to that location.

NSString *stuff = @"1464/sampletext1/sampletext2/sampletext3";
NSString *digits;
NSRange slashRange = [stuff rangeOfString:@"/"];
if (slashRange.location != NSNotFound) {
    digits = [stuff substringToIndex:slashRange.location];
} else {
    digits = stuff;
}

edited Sep 17 '13 at 21:24

answered Sep 17 '13 at 21:18

rmaddy

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thanks. any idea why I would get an "initializing 'NSRange *' (aka struct _NSRange) with an incompatible type NSRange? – user2588945 Sep 17 '13 at 21:23
Sorry, typo - don't use a pointer with the `slashRange` variable. – rmaddy Sep 17 '13 at 21:24

Brian Nickel · Accepted Answer · 2013-09-17T22:47:42.980

You mentioned that you extracted a web address from the front, so I'm guessing you're dealing with either something like http://localhost:12345/a/b/c or http://localhost/12345/a/b/c.

In either case, you can convert your string to an NSURL and take advantage of its built-in features:

// Port
NSURL *URL = [NSURL URLWithString:@"http://localhost:12345/a/b/c"];
NSUInteger port = URL.port.integerValue;

// Path component
NSURL *URL = [NSURL URLWithString:@"http://localhost/12345/a/b/c"];
NSString *number = URL.pathComponents[1];

score 0 · Answer 3 · answered Sep 17 '13 at 21:58

Use regular expressions:

NSError *error;
NSString *test = @"1464/sampletext1/sampletext2/sampletext3";
NSRegularExpression *aRegex = [NSRegularExpression regularExpressionWithPattern:@"^\\d+"
                                                                        options:NSRegularExpressionCaseInsensitive
                                                                          error:&error];

NSRange aRangeOfFirstMatch = [aRegex rangeOfFirstMatchInString:test options:0 range:NSMakeRange(0, [test length])];

if (aRangeOfFirstMatch.location != NSNotFound) {
    NSString *matchedString = [test substringWithRange:aRangeOfFirstMatch];
    NSLog(@"matchedString = %@", matchedString);
}

How to strip part of an NSString after the first instance of a character?

3 Answers3