Convert an iPhone phone number format for a "dial-able" string

Question

I am building an iphone app that reads a phone number from the address book and dial it (with some other things of course...:)). When I load the phone numbers from the AB they are in this following format: "1 (111) 111-1111" which is not "dial-able" when using this:

fullNumber = [NSString stringWithFormat:@"%@%@", @"tel:", phoneNum];

Why is that happening? What would be the best way to approach this? How could I convert the phone number into a string of digits (with no spaces or "-")?

Thanks.

Answer 1

This will strip out all non-numeric characters:

phoneNumDecimalsOnly = [[phoneNum componentsSeparatedByCharactersInSet:[[NSCharacterSet decimalDigitCharacterSet] invertedSet]] componentsJoinedByString:@""];

Answer 2

The below code will allow only digits and + in the entered string.

phoneNumber = [[phoneNumber componentsSeparatedByCharactersInSet:
            [[NSCharacterSet characterSetWithCharactersInString:@"+0123456789"]
             invertedSet]]
           componentsJoinedByString:@""];

Answer 3

To answer your question about removing specific characters from a string... Take a look at the NSString Class Reference specifcally the method stringByReplacingOccurrencesOfString:withString:

You could do

fullNumer = [fullNumber stringByReplacingOccurrencesOfString:@"(" withString:@""];
fullNumer = [fullNumber stringByReplacingOccurrencesOfString:@")" withString:@""];
fullNumer = [fullNumber stringByReplacingOccurrencesOfString:@"-" withString:@""];
fullNumer = [fullNumber stringByReplacingOccurrencesOfString:@" " withString:@""];

Obviously not the most efficient... but it should give you an idea of the method and how to strip out specific characters.

Another option that covers any character other than a number can be seen in the following SO post, this is likely a much better solution to your problem.

Remove all but numbers from NSString