I have an NSAttributedString like so:
NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:#"EThis string shows my #tags. Click on a #tag now."];
What do I use to find the location and end of all tags? Is there a good regex for this or another better way in iOS?
Note: My definition of a tag starts with # and ends with the last alphanumeric character is hit. So a period (.), space, or dash would end the tag.
Thanks.
Seems like you want something like this,
#.*?[A-Za-z0-9](?=[.\\s-])
or
#.*?[A-Za-z0-9](?=[. -])
The above regex would match all the strings which starts with # then matches upto the first alphanumeric character which is immediately followed by a space or dot or dash.
DEMO
If you want to extract the string then you can use NSScanner class like that below:-
NSMutableAttributedString *mtStr = [[NSMutableAttributedString alloc]initWithString:#"EThis string shows my #tags. Click on a #tag now."];
NSString *string = mtStr.string;
// Set up convenience variables for the start and end tag;
NSString *startTag = #"#";
NSString *endTag = #".";
NSString *title;
NSScanner *scanner = [NSScanner scannerWithString:string];
[scanner scanUpToString:startTag intoString:nil];
[scanner scanString:startTag intoString:nil];
[scanner scanUpToString:endTag intoString:&title];
NSLog(#"Value is: %#", title);
The class you need is NSRegularExpression and the particular method that will give you the start and length of each match is matchesInString:options:range.
I have an NSString (phone number) with some parenthesis and hyphens as some phone numbers are formatted. How would I remove all characters except numbers from the string?
Old question, but how about:
NSString *newString = [[origString componentsSeparatedByCharactersInSet:
[[NSCharacterSet decimalDigitCharacterSet] invertedSet]]
componentsJoinedByString:#""];
It explodes the source string on the set of non-digits, then reassembles them using an empty string separator. Not as efficient as picking through characters, but much more compact in code.
There's no need to use a regular expressions library as the other answers suggest -- the class you're after is called NSScanner. It's used as follows:
NSString *originalString = #"(123) 123123 abc";
NSMutableString *strippedString = [NSMutableString
stringWithCapacity:originalString.length];
NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *numbers = [NSCharacterSet
characterSetWithCharactersInString:#"0123456789"];
while ([scanner isAtEnd] == NO) {
NSString *buffer;
if ([scanner scanCharactersFromSet:numbers intoString:&buffer]) {
[strippedString appendString:buffer];
} else {
[scanner setScanLocation:([scanner scanLocation] + 1)];
}
}
NSLog(#"%#", strippedString); // "123123123"
EDIT: I've updated the code because the original was written off the top of my head and I figured it would be enough to point the people in the right direction. It seems that people are after code they can just copy-paste straight into their application.
I also agree that Michael Pelz-Sherman's solution is more appropriate than using NSScanner, so you might want to take a look at that.
The accepted answer is overkill for what is being asked. This is much simpler:
NSString *pureNumbers = [[phoneNumberString componentsSeparatedByCharactersInSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]] componentsJoinedByString:#""];
This is great, but the code does not work for me on the iPhone 3.0 SDK.
If I define strippedString as you show here, I get a BAD ACCESS error when trying to print it after the scanCharactersFromSet:intoString call.
If I do it like so:
NSMutableString *strippedString = [NSMutableString stringWithCapacity:10];
I end up with an empty string, but the code doesn't crash.
I had to resort to good old C instead:
for (int i=0; i<[phoneNumber length]; i++) {
if (isdigit([phoneNumber characterAtIndex:i])) {
[strippedString appendFormat:#"%c",[phoneNumber characterAtIndex:i]];
}
}
Though this is an old question with working answers, I missed international format support. Based on the solution of simonobo, the altered character set includes a plus sign "+". International phone numbers are supported by this amendment as well.
NSString *condensedPhoneNumber = [[phoneNumber componentsSeparatedByCharactersInSet:
[[NSCharacterSet characterSetWithCharactersInString:#"+0123456789"]
invertedSet]]
componentsJoinedByString:#""];
The Swift expressions are
var phoneNumber = " +1 (234) 567-1000 "
var allowedCharactersSet = NSMutableCharacterSet.decimalDigitCharacterSet()
allowedCharactersSet.addCharactersInString("+")
var condensedPhoneNumber = phoneNumber.componentsSeparatedByCharactersInSet(allowedCharactersSet.invertedSet).joinWithSeparator("")
Which yields +12345671000 as a common international phone number format.
Here is the Swift version of this.
import UIKit
import Foundation
var phoneNumber = " 1 (888) 555-5551 "
var strippedPhoneNumber = "".join(phoneNumber.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet))
Swift version of the most popular answer:
var newString = join("", oldString.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet))
Edit: Syntax for Swift 2
let newString = oldString.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet).joinWithSeparator("")
Edit: Syntax for Swift 3
let newString = oldString.components(separatedBy: CharacterSet.decimalDigits.inverted).joined(separator: "")
Thanks for the example. It has only one thing missing the increment of the scanLocation in case one of the characters in originalString is not found inside the numbers CharacterSet object. I have added an else {} statement to fix this.
NSString *originalString = #"(123) 123123 abc";
NSMutableString *strippedString = [NSMutableString
stringWithCapacity:originalString.length];
NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *numbers = [NSCharacterSet
characterSetWithCharactersInString:#"0123456789"];
while ([scanner isAtEnd] == NO) {
NSString *buffer;
if ([scanner scanCharactersFromSet:numbers intoString:&buffer]) {
[strippedString appendString:buffer];
}
// --------- Add the following to get out of endless loop
else {
[scanner setScanLocation:([scanner scanLocation] + 1)];
}
// --------- End of addition
}
NSLog(#"%#", strippedString); // "123123123"
It Accept only mobile number
NSString * strippedNumber = [mobileNumber stringByReplacingOccurrencesOfString:#"[^0-9]" withString:#"" options:NSRegularExpressionSearch range:NSMakeRange(0, [mobileNumber length])];
It might be worth noting that the accepted componentsSeparatedByCharactersInSet: and componentsJoinedByString:-based answer is not a memory-efficient solution. It allocates memory for the character set, for an array and for a new string. Even if these are only temporary allocations, processing lots of strings this way can quickly fill the memory.
A memory friendlier approach would be to operate on a mutable copy of the string in place. In a category over NSString:
-(NSString *)stringWithNonDigitsRemoved {
static NSCharacterSet *decimalDigits;
if (!decimalDigits) {
decimalDigits = [NSCharacterSet decimalDigitCharacterSet];
}
NSMutableString *stringWithNonDigitsRemoved = [self mutableCopy];
for (CFIndex index = 0; index < stringWithNonDigitsRemoved.length; ++index) {
unichar c = [stringWithNonDigitsRemoved characterAtIndex: index];
if (![decimalDigits characterIsMember: c]) {
[stringWithNonDigitsRemoved deleteCharactersInRange: NSMakeRange(index, 1)];
index -= 1;
}
}
return [stringWithNonDigitsRemoved copy];
}
Profiling the two approaches have shown this using about 2/3 less memory.
You can use regular expression on mutable string:
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:
#"[^\\d]"
options:0
error:nil];
[regex replaceMatchesInString:str
options:0
range:NSMakeRange(0, str.length)
withTemplate:#""];
Built the top solution as a category to help with broader problems:
Interface:
#interface NSString (easyReplace)
- (NSString *)stringByReplacingCharactersNotInSet:(NSCharacterSet *)set
with:(NSString *)string;
#end
Implemenation:
#implementation NSString (easyReplace)
- (NSString *)stringByReplacingCharactersNotInSet:(NSCharacterSet *)set
with:(NSString *)string
{
NSMutableString *strippedString = [NSMutableString
stringWithCapacity:self.length];
NSScanner *scanner = [NSScanner scannerWithString:self];
while ([scanner isAtEnd] == NO) {
NSString *buffer;
if ([scanner scanCharactersFromSet:set intoString:&buffer]) {
[strippedString appendString:buffer];
} else {
[scanner setScanLocation:([scanner scanLocation] + 1)];
[strippedString appendString:string];
}
}
return [NSString stringWithString:strippedString];
}
#end
Usage:
NSString *strippedString =
[originalString stringByReplacingCharactersNotInSet:
[NSCharacterSet setWithCharactersInString:#"01234567890"
with:#""];
Swift 3
let notNumberCharacters = NSCharacterSet.decimalDigits.inverted
let intString = yourString.trimmingCharacters(in: notNumberCharacters)
swift 4.1
var str = "75003 Paris, France"
var stringWithoutDigit = (str.components(separatedBy:CharacterSet.decimalDigits)).joined(separator: "")
print(stringWithoutDigit)
Um. The first answer seems totally wrong to me. NSScanner is really meant for parsing. Unlike regex, it has you parsing the string one tiny chunk at a time. You initialize it with a string, and it maintains an index of how far along the string it's gotten; That index is always its reference point, and any commands you give it are relative to that point. You tell it, "ok, give me the next chunk of characters in this set" or "give me the integer you find in the string", and those start at the current index, and move forward until they find something that doesn't match. If the very first character already doesn't match, then the method returns NO, and the index doesn't increment.
The code in the first example is scanning "(123)456-7890" for decimal characters, which already fails from the very first character, so the call to scanCharactersFromSet:intoString: leaves the passed-in strippedString alone, and returns NO; The code totally ignores checking the return value, leaving the strippedString unassigned. Even if the first character were a digit, that code would fail, since it would only return the digits it finds up until the first dash or paren or whatever.
If you really wanted to use NSScanner, you could put something like that in a loop, and keep checking for a NO return value, and if you get that you can increment the scanLocation and scan again; and you also have to check isAtEnd, and yada yada yada. In short, wrong tool for the job. Michael's solution is better.
For those searching for phone extraction, you can extract the phone numbers from a text using NSDataDetector, for example:
NSString *userBody = #"This is a text with 30612312232 my phone";
if (userBody != nil) {
NSError *error = NULL;
NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypePhoneNumber error:&error];
NSArray *matches = [detector matchesInString:userBody options:0 range:NSMakeRange(0, [userBody length])];
if (matches != nil) {
for (NSTextCheckingResult *match in matches) {
if ([match resultType] == NSTextCheckingTypePhoneNumber) {
DbgLog(#"Found phone number %#", [match phoneNumber]);
}
}
}
}
`
I created a category on NSString to simplify this common operation.
NSString+AllowCharactersInSet.h
#interface NSString (AllowCharactersInSet)
- (NSString *)stringByAllowingOnlyCharactersInSet:(NSCharacterSet *)characterSet;
#end
NSString+AllowCharactersInSet.m
#implementation NSString (AllowCharactersInSet)
- (NSString *)stringByAllowingOnlyCharactersInSet:(NSCharacterSet *)characterSet {
NSMutableString *strippedString = [NSMutableString
stringWithCapacity:self.length];
NSScanner *scanner = [NSScanner scannerWithString:self];
while (!scanner.isAtEnd) {
NSString *buffer = nil;
if ([scanner scanCharactersFromSet:characterSet intoString:&buffer]) {
[strippedString appendString:buffer];
} else {
scanner.scanLocation = scanner.scanLocation + 1;
}
}
return strippedString;
}
#end
I think currently best way is:
phoneNumber.replacingOccurrences(of: "\\D",
with: "",
options: String.CompareOptions.regularExpression)
If you're just looking to grab the numbers from the string, you could certainly use regular expressions to parse them out. For doing regex in Objective-C, check out RegexKit. Edit: As #Nathan points out, using NSScanner is a much simpler way to parse all numbers from a string. I totally wasn't aware of that option, so props to him for suggesting it. (I don't even like using regex myself, so I prefer approaches that don't require them.)
If you want to format phone numbers for display, it's worth taking a look at NSNumberFormatter. I suggest you read through this related SO question for tips on doing so. Remember that phone numbers are formatted differently depending on location and/or locale.
Swift 5
let newString = origString.components(separatedBy: CharacterSet.decimalDigits.inverted).joined(separator: "")
Based on Jon Vogel's answer here it is as a Swift String extension along with some basic tests.
import Foundation
extension String {
func stringByRemovingNonNumericCharacters() -> String {
return self.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet).joinWithSeparator("")
}
}
And some tests proving at least basic functionality:
import XCTest
class StringExtensionTests: XCTestCase {
func testStringByRemovingNonNumericCharacters() {
let baseString = "123"
var testString = baseString
var newString = testString.stringByRemovingNonNumericCharacters()
XCTAssertTrue(newString == testString)
testString = "a123b"
newString = testString.stringByRemovingNonNumericCharacters()
XCTAssertTrue(newString == baseString)
testString = "a=1-2_3#b"
newString = testString.stringByRemovingNonNumericCharacters()
XCTAssertTrue(newString == baseString)
testString = "(999) 999-9999"
newString = testString.stringByRemovingNonNumericCharacters()
XCTAssertTrue(newString.characters.count == 10)
XCTAssertTrue(newString == "9999999999")
testString = "abc"
newString = testString.stringByRemovingNonNumericCharacters()
XCTAssertTrue(newString == "")
}
}
This answers the OP's question but it could be easily modified to leave in phone number related characters like ",;*#+"
NSString *originalPhoneNumber = #"(123) 123-456 abc";
NSCharacterSet *numbers = [[NSCharacterSet characterSetWithCharactersInString:#"0123456789"] invertedSet];
NSString *trimmedPhoneNumber = [originalPhoneNumber stringByTrimmingCharactersInSet:numbers];
];
Keep it simple!
I have an NSString *fileName
This will contain a variable number from 1 to 3 digits. I want to extract all of the digits
I can get the first digit using
//create text for appliance identifier
char obsNumber = [fileName characterAtIndex:3];//get 4 character
NSLog(#"Obs number %c",obsNumber);
//Text label
[cell.titleLabel setText:[NSString stringWithFormat:#"Item No: %c",obsNumber]];
NSLog(#"Label for observation = %#",cell.titleLabel.text);
However if the string contains the number for example 78, or 204 I want to catch all two or three digits.
I tried this
//create text for appliance identifier
char obsNumber1 = [fileName characterAtIndex:3];//get 4 character
char obsNumber2 = [fileName characterAtIndex:4];//get 5 character
char obsNumber3 = [fileName characterAtIndex:5];//get 6 character
NSLog(#"Obs number %c,%c,%c",obsNumber1,obsNumber2,obsNumber3);
//Text label
[cell.titleLabel setText:[NSString stringWithFormat:#"Item No: %c,%c,%c",obsNumber1,obsNumber2,obsNumber3]];
NSLog(#"Label for observation = %#",cell.titleLabel.text);
This gave me 18c 1ce etc
Would this work for you?
NSString *filename = #"obs127observation"; //An example variable with your format
This code could be tidier but you should get the idea:
NSString *filenameNumber = [[filename
stringByReplacingOccurrencesOfString:#"observation"
withString:#""]
stringByReplacingOccurrencesOfString:#"obs"
withString:#""];
you can trim other letters except the decimals.
NSString *onlyNumbers=[yourstring stringByTrimmingCharactersInSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]];
As your comment says , It has predefined set of values, right. Then try like this
NSstring *str = [filename substringFromIndex:11];
// Convert the str to char[]
Then you should try with the NSScanner :
NSString *numberString;
NSScanner *scanner = [NSScanner scannerWithString:filename];
NSCharacterSet *numbers = [NSCharacterSet characterSetWithCharactersInString:#"0123456789"];
// Throw away characters before the first number.
[scanner scanUpToCharactersFromSet:numbers intoString:NULL];
// Collect numbers.
[scanner scanCharactersFromSet:numbers intoString:&numberString];
// Result.
int number = [numberString integerValue];
// you can play around with the set of number
Your approach of separating one character at a time and then combining them back into a string is an awkward, overly complex way of going about this. Kumar's suggestion of using NSScanner is a good option if you have a number in the middle of a string.
However, you make it sound like your string will always contain a number and only a number. Is that true? Or will there be characters you need to ignore?
You need to define the problem clearly and completely before you can select the best solution.
It might be as simple as using the NSString method substringWithRange.
How can I get the unique characters in an NSString?
What I'm trying to do is get all the illegal characters in an NSString so that I can prompt the user which ones were inputted and therefore need to be removed. I start off by defining an NSCharacterSet of legal characters, separate them with every occurrence of a legal character, and join what's left (only illegal ones) into a new NSString. I'm now planning to get the unique characters of the new NSString (as an array, hopefully), but I couldn't find a reference anywhere.
NSCharacterSet *legalCharacterSet = [NSCharacterSet
characterSetWithCharactersInString:#"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789-()&+:;,'.# "];
NSString *illegalCharactersInTitle = [[self.titleTextField.text.noWhitespace
componentsSeparatedByCharactersInSet:legalCharacterSet]
componentsJoinedByString:#""];
That should help you. I couldn't find any ready to use function for that.
NSMutableSet *uniqueCharacters = [NSMutableSet set];
NSMutableString *uniqueString = [NSMutableString string];
[illegalCharactersInTitle enumerateSubstringsInRange:NSMakeRange(0, illegalCharactersInTitle.length) options:NSStringEnumerationByComposedCharacterSequences usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
if (![uniqueCharacters containsObject:substring]) {
[uniqueCharacters addObject:substring];
[uniqueString appendString:substring];
}
}];
Try with the following adaptation of your code:
// legal set
NSCharacterSet *legalCharacterSet = [NSCharacterSet
characterSetWithCharactersInString:#"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789-()&+:;,'.# "];
// test strings
NSString *myString = #"LegalStrin()";
//NSString *myString = #"francesco#gmail.com"; illegal string
NSMutableCharacterSet *stringSet = [NSCharacterSet characterSetWithCharactersInString:myString];
// inverts the set
NSCharacterSet *illegalCharacterSet = [legalCharacterSet invertedSet];
// intersection of the string set and the illegal set that modifies the mutable stringset itself
[stringSet formIntersectionWithCharacterSet:illegalCharacterSet];
// prints out the illegal characters with the convenience method
NSLog(#"IllegalStringSet: %#", [self stringForCharacterSet:stringSet]);
I adapted the method to print from another stackoverflow question:
- (NSString*)stringForCharacterSet:(NSCharacterSet*)characterSet
{
NSMutableString *toReturn = [#"" mutableCopy];
unichar unicharBuffer[20];
int index = 0;
for (unichar uc = 0; uc < (0xFFFF); uc ++)
{
if ([characterSet characterIsMember:uc])
{
unicharBuffer[index] = uc;
index ++;
if (index == 20)
{
NSString * characters = [NSString stringWithCharacters:unicharBuffer length:index];
[toReturn appendString:characters];
index = 0;
}
}
}
if (index != 0)
{
NSString * characters = [NSString stringWithCharacters:unicharBuffer length:index];
[toReturn appendString:characters];
}
return toReturn;
}
First of all, you have to be careful about what you consider characters. The API of NSString uses the word characters when talking about what Unicode refers to as UTF-16 code units, but dealing with code units in isolation will not give you what users think of as characters. For example, there are combining characters that compose with the previous character to produce a different glyph. Also, there are surrogate pairs, which only make sense when, um, paired.
As a result, you will actually need to collect substrings which contain what the user thinks of as characters.
I was about to write code very similar to Grzegorz Krukowski's answer. He beat me to it, so I won't but I will add that your code to filter out the legal characters is broken because of the reasons I cite above. For example, if the text contains "é" and it's decomposed as "e" plus a combining acute accent, your code will strip the "e", leaving a dangling combining acute accent. I believe your intent is to treat the "é" as illegal.
Is there any way to extract substring from a string like below
My real string is "NS09A" or "AB455A" but i want only "NS09" or "AB455" (upto the end of numeric part of original string).
How can i extract this?
I saw google search answers like using position of starting and endinf part of substring we can extract that ,But here any combination of "Alphabets+number+alphabets" .I need only " "Alphabets+number"
Perhaps not everybody will agree, but I like regular expressions. They allow to specify
precisely what you are looking for:
NSString *string = #"AB455A";
// One or more "word characters", followed by one or more "digits":
NSString *pattern = #"\\w+\\d+";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern
options:0
error:NULL];
NSTextCheckingResult *match = [regex firstMatchInString:string
options:NSMatchingAnchored
range:NSMakeRange(0, [string length])];
if (match != nil) {
NSString *extracted = [string substringWithRange:[match range]];
NSLog(#"%#", extracted);
// Output: AB455
} else {
// Input string is not of the expected form.
}
Try This:-
NSString *str=#"ASRF12353FYTEW";
NSString *resultStr;
for(int i=0;i<[str length];i++){
NSString *character = [str substringFromIndex: [str length] - i];
if([character intValue]){
resultStr=[str substringToIndex:[str length]-i+1];
break;
}
}
NSLog(#"RESUKT STRING %#",resultStr);
I tested this code:
NSString *originalString = #"NS09A";
// Intermediate
NSString *numberString;
NSString *numberString1;
NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *numbers = [NSCharacterSet characterSetWithCharactersInString:#"0123456789"];
[scanner scanUpToCharactersFromSet:numbers intoString:&numberString];
[scanner scanCharactersFromSet:numbers intoString:&numberString1];
NSString *result=[NSString stringWithFormat:#"%#%#",numberString,numberString1];
NSLog(#"Finally ==%#",result);
Hope it Help You
OUTPUT
Finally ==NS09
UPDATE:
NSString *originalString = #"kirtimali#gmail.com";
NSString *result;
NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *cs1 = [NSCharacterSet characterSetWithCharactersInString:#"#"];
[scanner scanUpToCharactersFromSet:cs1 intoString:&result];
NSLog(#"Finally ==%#",result);
output:
Finally ==kirtimali
Use NSScanner and the scanUpToCharactersFromSet:intoString: method to specify which characters should be used to stop the parsing. This could be in a loop with some logic or it could be applied in conjunction with setScanLocation: if you already have a method of finding the start of each section you want to extract.
When using scanUpToCharactersFromSet:intoString: you are looking for the next invalid character. It doesn't need to be a 'special' character (in a unicode sense), just a known set of characters that aren't valid for the content you want. So, you might use:
[[NSCharacterSet characterSetWithCharactersInString:#"1234567890"] invertedSet]
You can use - (NSString *)substringWithRange:(NSRange)aRange method on NSString class to get a substring extracted. Use NSMakeRange to create the NSRange object.