---
title: NSDataDetector
framework: foundation
role: symbol
role_heading: Class
path: foundation/nsdatadetector
---

# NSDataDetector

A specialized regular expression object that matches natural language text for predefined data patterns.

## Declaration

```swift
class NSDataDetector
```

## Overview

Overview Find dates, addresses, links, phone numbers, and transit information in natural language text with NSDataDetector. NSDataDetector returns the results of matching content in NSTextCheckingResult objects. The NSTextCheckingResult objects that NSDataDetector returns are different from those that NSRegularExpression returns. The results are one of the data detector’s types and contain the corresponding properties. For example, results of type date have a date, timeZone, and duration; and results of type link have a url. important: Don’t use NSDataDetector to validate data. NSDataDetector discards potential matches in case of uncertainty. Use a class specific to the type of data for validation instead. For example, attempt to instantiate a URL object using init(string:) to validate a URL string. A valid URL string returns an instance of URL, while an invalid URL string returns nil. Examples The following shows several graduated examples of using the NSDataDetector class. This code fragment creates a data detector that finds URL links and phone numbers. If an error occurs, it returns in error.    NSError *error = nil;    NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink|NSTextCheckingTypePhoneNumber                                                               error:&error]; After creating the data detector instance, you can determine the number of matches within a range of a string using the NSRegularExpression method numberOfMatches(in:options:range:).    NSUInteger numberOfMatches = [detector numberOfMatchesInString:string                                                           options:0                                                             range:NSMakeRange(0, [string length])]; If you’re interested only in the overall range of the first match, the numberOfMatches(in:options:range:) method provides it.  However, with data detectors, this is less likely than with regular expressions because clients are usually interested in additional information as well. The additional information available depends on the type of the result.  For results of type link, it’s the URL property that’s significant.  For results of type NSTextCheckingTypePhoneNumber , it’s the phoneNumber property instead. The matches(in:options:range:) method is similar to firstMatch(in:options:range:), except that it returns all matches rather than only the first. The following code fragment finds all the matches for links and phone numbers in a string:    NSArray *matches = [detector matchesInString:string                                         options:0                                           range:NSMakeRange(0, [string length])];    for (NSTextCheckingResult *match in matches) {         NSRange matchRange = [match range];         if ([match resultType] == NSTextCheckingTypeLink) {             NSURL *url = [match URL];         } else if ([match resultType] == NSTextCheckingTypePhoneNumber) {             NSString *phoneNumber = [match phoneNumber];         }    } The NSRegularExpression block object enumerator is the most general and flexible of the matching methods.  It allows you to iterate through matches in a string, performing arbitrary actions on each as specified by the code in the block, and to stop partway through if desired. In the following code fragment, the iteration stops after finding a certain number of matches:    __block NSUInteger count = 0;    [detector enumerateMatchesInString:string                               options:0                                 range:NSMakeRange(0, [string length])                            usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop){         NSRange matchRange = [match range];         if ([match resultType] == NSTextCheckingTypeLink) {             NSURL *url = [match URL];         } else if ([match resultType] == NSTextCheckingTypePhoneNumber) {             NSString *phoneNumber = [match phoneNumber];         }         if (++count >= 100) *stop = YES;    }]; note: Only use NSDataDetector on natural language text. If you expect text to be in a particular format, use an Formatter or ValueTransformer subclass instead. For instance, if you’re expecting a date field to be an ISO 8601 timestamp, use DateFormatter to parse that into an NSDate object. If the text is in a machine-readable format, such as XML or JSON, extract the natural language text, such as by using XMLParser or JSONSerialization, and match on that rather than attempt to match on the entire document.

## Topics

### Creating data detector instances

- [init(types:)](foundation/nsdatadetector/init(types:).md)

### Getting the checking types

- [checkingTypes](foundation/nsdatadetector/checkingtypes.md)

## Relationships

### Inherits From

- [NSRegularExpression](foundation/nsregularexpression.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCoding](foundation/nscoding.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSSecureCoding](foundation/nssecurecoding.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Pattern Matching

- [Scanner](foundation/scanner.md)
- [NSRegularExpression](foundation/nsregularexpression.md)
- [NSTextCheckingResult](foundation/nstextcheckingresult.md)
- [NSNotFound](foundation/nsnotfound-4qp9h.md)