I am developing an iOS app and need to remove all text between brackets from a string, including the brackets. Example: "Look at this image [960x640]" should be "Look at this image"
My code works fine if there's only one set of brackets, but if there's multiple, it only removes the first set.
+ (NSString *)stringWithoutBrackets:(NSString *)input{
NSString *expression = #"\\[[\\w]+\\]";
while ([input rangeOfString:expression options:NSRegularExpressionSearch|NSCaseInsensitiveSearch].location!=NSNotFound){
input = [input stringByReplacingOccurrencesOfString:expression withString:#"" options:NSRegularExpressionSearch|NSCaseInsensitiveSearch range:NSMakeRange(0, [input length])];
}
return input;
}
Try using the NSRegularExpression class.
NSError *error;
NSMutableString *string = [NSMutableString stringWithString:#"Look at this image [960x640] and [somethingelse]"];
NSRegularExpression *regularExpression = [NSRegularExpression regularExpressionWithPattern:#"\\\[[\\\w]+\\\]" options:0 error:&error];
[regularExpression replaceMatchesInString:string options:0 range:NSMakeRange(0, string.length) withTemplate:#""];
NSLog(#"String %#", string);
Prints:Look at this image and
Related
I have two strings as followed:
NSString *newStr = #"143.2a";
NSString *expression = #"^([0-9]*)(\\.([0-9]{0,10})?)?$";
I want to substring "newStr" such as all my characters in "expression" should be present after subString. Like
NSString * extractedString = #"143.2";
(except all alphabets and symbols other than single'.')
How shall I do this?
First of all, your regex pattern won't extract that string.
If you want to check for one or more digits followed be a dot followed be one or more digits the pattern is supposed to be
NSString *expression = #"\\d+\\.\\d+";
To extract the string use the NSRegularExpression class as suggested by Larme.
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:expression options:0 error:nil];
NSTextCheckingResult *firstMatch = [regex firstMatchInString:newStr options:0 range:NSMakeRange(0, newStr.length)];
if (firstMatch) {
NSString *extractedString = [newStr substringWithRange:firstMatch.range];
NSLog(#"%#", extractedString);
} else {
NSLog(#"Not Found");
}
I am trying to remove all symbols from a string, it works fine with below code for all symbols except "?".
NSString *newString = self.titleString;
NSArray *characters = #[#"<", #"!", #"#", #"#", #"$", #"%", #"^", #"&", #"*", #"(", #")", #",", #"_", #"+", #"|", #">", #"?", #" "];
for (NSString *str in characters) {
newString = [newString stringByReplacingOccurrencesOfString:str withString:#""];
}
You can use stringByReplacingOccurrencesOfString with the regular expression option, NSRegularExpressionSearch:
NSString *output = [input stringByReplacingOccurrencesOfString:#"[<>!##$%^&*(),_+?| ]" withString:#"" options:NSRegularExpressionSearch range:NSMakeRange(0, [input length])];
You can also take advantage of other regular expression features, e.g. replace all non-letter characters:
NSString *output = [input stringByReplacingOccurrencesOfString:#"\\P{L}" withString:#"" options:NSRegularExpressionSearch range:NSMakeRange(0, [input length])];
or not A-Z:
NSString *output = [input stringByReplacingOccurrencesOfString:#"[^a-zA-Z]" withString:#"" options:NSRegularExpressionSearch range:NSMakeRange(0, [input length])];
It just depends upon precisely what you're trying to achieve.
You can remove all characters in a single call using NSRegularExpression:
NSString *string = self.titleString;
NSError *error = nil;
// Prepare the regular expression that matches any of your characters
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"[<>!##$%^&*(),_+?| ]"
options:NSRegularExpressionCaseInsensitive
error:&error];
// Replace all matches with an empty string
string = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:#""];
You have to escape the ? like that: "\?". Otherwise it won't work properly. ? only means in regex stands for 0 or 1 occurences and so you have to say to objective-c that it is a real char you want to test.
If this is for editing user text you might want to consider using a union of more than one NSCharacterSet - this will help it be more language-friendly when you localize/internationalize your app.
NSString *myInputText = #"asd;jkfhals#$%^%$&1asldiguhd";
NSCharacterSet *nonAlphanumeric = [[NSMutableCharacterSet alphanumericCharacterSet] invert];
NSArray *parts = [myInputText componentsSeparatedByCharactersInSet:nonAlphanumeric];
NSArray *mySafeOutputText = [parts componentsJoinedByString:#""];
It's a little non-intuitive to use the components method, but unfortunately Apple doesn't provide a stringByReplacingCharactersInSet: method. :(
I have an NSString as:
"<a href='javascript:void(null)' onclick='handleCommandForAnchor(this, 10);return false;'>12321<\/a>"
I need to extract the 12321 near the end of the NSString from it and store.
First I tried
NSString *shipNumHtml=[mValues objectAtIndex:1];
NSInteger htmlLen=[shipNumHtml length];
NSString *shipNum=[[shipNumHtml substringFromIndex:htmlLen-12]substringToIndex:8];
But then I found out that number 12321 can be of variable length.
I can't find a method like java's indexOf() to find the '>' and '<' and then find substring with those indices. All the answers I've found on SO either know what substring to search for or know the location if the substring. Any help?
I don't usually advocate using Regular expressions for parsing HTML contents but it seems a regex matching >(\d+)< would to the job in this simple string.
Here is a simple example:
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#">(\\d+)<"
options:0
error:&error];
// Handle error != nil
NSTextCheckingResult *match = [regex firstMatchInString:string
options:0
range:NSMakeRange(0, [string length])];
if (match) {
NSRange matchRange = [match rangeAtIndex:1];
NSString *number = [string substringWithRange:matchRange]
NSLog(#"Number: %#", number);
}
As #HaneTV says, you can use the NSString method rangeOfString to search for substrings. Given that the characters ">" and "<" appear in multiple places in your string, so you might want to take a look at NSRegularExpression and/or NSScanner.
that may help on you a bit, I've just tested:
NSString *_string = #"<a href='javascript:void(null)' onclick='handleCommandForAnchor(this, 10);return false;'>12321</a>";
NSError *_error;
NSRegularExpression *_regExp = [NSRegularExpression regularExpressionWithPattern:#">(.*)<" options:NSRegularExpressionCaseInsensitive error:&_error];
NSArray *_matchesInString = [_regExp matchesInString:_string options:NSMatchingReportCompletion range:NSMakeRange(0, _string.length)];
[_matchesInString enumerateObjectsUsingBlock:^(NSTextCheckingResult * result, NSUInteger idx, BOOL *stop) {
for (int i = 0; i < result.numberOfRanges; i++) {
NSString *_match = [_string substringWithRange:[result rangeAtIndex:i]];
NSLog(#"%#", _match);
}
}];
Earlier I had string as 1,2,3,,5,6,7
To replace string, I used stringByReplacingOccurrencesOfString:#",," withString:#",", which gives output as 1,2,3,5,6,7
Now I have string as below.
1,2,3,,,6,7
To replace string, I used stringByReplacingOccurrencesOfString:#",," withString:#",", which gives output as 1,2,3,,6,7
Is there way where I can replace all double comma by single comma.
I know I can do it using for loop or while loop, but I want to check is there any other way?
for (int j=1;j<=100;j++) {
stringByReplacingOccurrencesOfString:#",," withString:#","]]
}
NSString *string = #"1,2,3,,,6,7";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#",{2,}" options:NSRegularExpressionCaseInsensitive error:&error];
NSString *modifiedString = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:#","];
NSLog(#"%#", modifiedString);
This will match any number of , present in the string. It's future proof :)
Not the perfect solution, but what about this
NSString *string = #"1,2,3,,,6,7";
NSMutableArray *array =[[string componentsSeparatedByString:#","] mutableCopy];
[array removeObject:#""];
NSLog(#"%#",[array componentsJoinedByString:#","]);
I need help with replacing occurrences of string with another string. Occurrency that needs to be detected is actually some kind of function:
%nx+a or %nx-a
where x and a are some numbers.
So for example %n10+2 or %n54-11.
I can't even use something like:
NSRange startRange = [snippetString rangeOfString:#"%n"];
because if I have two patterns within same string I'm checking I'll only get starting range of first one...
Thanks.
For something like this you could use an NSRegularExpression and use the method enumerateMatches:.
Or you can create your own loop.
The first is the easiest once you have the correct pattern.
Something like...
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"%n" options:0 error:nil];
NSString *string = #"%n10+2*%n2";
[regex enumerateMatchesInString:string
options:0
range:NSMakeRange(0, string.length)
usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
// here you will get each instance of a match to the pattern
}];
You will have to check the docs for NSRegularExpression to learn how to do what work you need to do with this.
Docs... https://developer.apple.com/library/mac/documentation/Foundation/Reference/NSRegularExpression_Class/Reference/Reference.html
I assume that you need to do something with those two numbers. I think the best way is to use a regular expression to extract what you need in one go.
NSString * string = #"some %n5-3 string %n11+98";
NSError * regexError = nil;
NSRegularExpression * regex = [NSRegularExpression regularExpressionWithPattern:#"%n(\\d+)([+-])(\\d+)"
options:0
error:®exError];
NSArray * matches = [regex matchesInString:string options:0 range:NSMakeRange(0, string.length)];
for (NSTextCheckingResult * match in matches) {
NSString * firstNumber = [string substringWithRange:[match rangeAtIndex:1]];
NSString * secondNumber = [string substringWithRange:[match rangeAtIndex:3]];
NSString * sign = [string substringWithRange:[match rangeAtIndex:2]];
// Do something useful with the numbers.
}
Of course if you just need to replace all the %n occurences with a constant string you can do that in one call:
NSString * result = [string stringByReplacingOccurrencesOfString:#"%n\\d+[+-]\\d+"
withString:#"here be dragons"
options:NSRegularExpressionSearch
range:NSMakeRange(0, string.length)];
Disclaimer: I didn't test this code. Minor bugs may be present.
Alter this code to match ur need
yourString = [yourString stringByReplacingOccurrencesOfString:#" +" withString:#" "options:NSRegularExpressionSearch range:NSMakeRange(0, yourString.length)];