Find dynamically word in NSString - ios

Question

NSString * stringExample1=#"www.mysite.com/word-4-word-1-1-word-word-2-word-817061.html";
NSString * stringExample2=#"www.mysite.com/word-4-5-1-1-word-1-5-word-11706555.html";
I try to find - and . Inside of NSString.
NSRange range = [string rangeOfString:#"-"];
NSUInteger start = range.location;
NSUInteger end = start + range.length;
NSRange rangeDot= [string rangeOfString:#"."];
NSUInteger startt = rangeDot.location;
NSUInteger endt = startt + rangeDot.length;
But it's can't be successful. It's showing first place. How can I get 817061 and 11706555 inside of Nstring?
Thank you .

Answer 1

This will work for you,
NSArray *strArry=[stringExample1 componentsSeparatedByString:#"-"];
NSString *result =[strArry lastObject];
NSString *resultstring= [result stringByReplacingOccurrencesOfString:#".html" withString:#""];

Answer 2

Are you trying to find if it contains at least one of - or . ?
You can use -rangeOfCharacterFromSet:
NSCharacterSet *CharacterSet = [NSCharacterSet characterSetWithCharactersInString:#"-."];
NSRange range = [YourString rangeOfCharacterFromSet:CharacterSet];
if (range.location == NSNotFound)
{
// no - or . in the string
}
else
{
// - or . are present
}

Answer 3

Try this simple Regular Expression.
NSString * stringExample1=#"www.mysite.com/word-4-word-1-1-word-word-2-word-84354354353.html";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression
regularExpressionWithPattern:#"(\\-\\d*\\.)"
options:0
error:&error];
NSRange range = [regex rangeOfFirstMatchInString:stringExample1
options:0
range:NSMakeRange(0, [stringExample1 length])];
range = NSMakeRange(range.location+1, range.length-2);
NSString *result = [stringExample1 substringWithRange:range];
NSLog(#"%#",result);

Answer 4

I think the best way to find the match is by using regulars expressions with NSRegularExpression.
NSString * stringEx=#"www.mysite.com/word-4-word-1-1-word-word-2-word-817061.html";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"-(\\d*).html$"
options:NSRegularExpressionCaseInsensitive
error:&error];
NSArray *matches = [regex matchesInString:stringEx options:NSMatchingReportCompletion range:NSMakeRange(0, [stringEx length])];
if ([matches count] > 0)
{
NSString* resultString = [stringEx substringWithRange:[matches[0] rangeAtIndex:1]];
NSLog(#"Matched: %#", resultString);
}
Make sure you use an extra \ escape character in the regex NSString whenever needed.
UPDATE
I did a test using the two different approaches (regex vs string splitting) with the code below:
NSDate *timeBefore = [NSDate date];
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"-(\\d*).html$"
options:NSRegularExpressionCaseInsensitive
error:&error];
for (int i = 0; i < 100000; i++)
{
NSArray *matches = [regex matchesInString:stringEx options:NSMatchingReportCompletion range:NSMakeRange(0, [stringEx length])];
if ([matches count] > 0)
{
NSString* resultString = [stringEx substringWithRange:[matches[0] rangeAtIndex:1]];
}
}
NSTimeInterval timeSpent = [timeBefore timeIntervalSinceNow];
NSLog(#"Time: %.5f", timeSpent*-1);
on the simulator the differences are not significant, but running on an iPhone 4 I got the following results:
2013-11-25 10:24:19.795 NotifApp[406:60b] Time: 11.45771 // string splitting
2013-11-25 10:25:10.451 NotifApp[412:60b] Time: 7.55713 // regex
so I guess the best approach depends on case to case.