Objective-C Language Check whether a string matches a pattern


Example

NSString *testString1 = @"(555) 123-5678";
NSString *testString2 = @"not a phone number";

NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^\\(\\d{3}\\) \\d{3}\\-\\d{4}$"
                                                                       options:NSRegularExpressionCaseInsensitive error:&error];

NSInteger result1 = [regex numberOfMatchesInString:testString1 options:0 range:NSMakeRange(0, testString1.length)];
NSInteger result2 = [regex numberOfMatchesInString:testString2 options:0 range:NSMakeRange(0, testString2.length)];

NSLog(@"Is string 1 a phone number? %@", result1 > 0 ? @"YES" : @"NO");
NSLog(@"Is string 2 a phone number? %@", result2 > 0 ? @"YES" : @"NO");

The output will show that the first string is a phone number and the second one isn't.