Replacing to tidy strings

You've seen one common strategy to pull variables out of strings is to split the string based on a pattern. Sometimes, it's easier to just replace the parts you don't want with an empty string "". This is also a common strategy to clean strings up, for example, to remove unwanted punctuation or white space.

In this exercise you'll pull out some numbers by replacing the part of the string that isn't a number, you'll also play with the format of some phone numbers. Pay close attention to the difference between str_replace() and str_replace_all().