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Changing phone format (TODO) 140AnswerWhat’s the pattern?We want to match only phone numbers that contain exactly 10 digits (with optional spaces/hyphens)on a single line.In order to do this, we make our regex more rigid. We can do this by using the line anchors ˆ and $to indicate that we don’t expect any other kinds of characters besides the 10-digits and the optionalhypens/spaces.Find ˆ(\d{3})[ \-]?(\d{3})[ \-]?(\d{4})$Replace (\1)-\2-\3If you apply it to these sample numbers:255561640405556164040You will end up with:25556164040(555)-616-4040The first number is not transformed because it is not matched by the pattern.Exercise: Dial 1? If you’ve ever moved from office to office, one of the perplexing questions is:Do I have to dial 1 to make an outside call?So some people are used to having 1- be a part of their phone number, especially if they’re usingtheir office phone. Some of these people might add this prefix to their number out of reflex:1-555-241-5010555 981 270591124000001 101-555-7745AnswerIn English The same as before, except that the ten-digits might be preceded with the digit 1 andalso might be preceded by a hyphen or a whitespace character. There’s no new techniquehere. We just need to use the ? operator at least once more.Find ˆ1?[ \-]?(\d{3})[ \-]?(\d{3})[ \-]?(\d{4})$