Creating a Sample Application: Smart Form MailFormatting StringsTrimming Strings: chop(), ltrim(), and trim()Formatting Strings for OutputJoining and Splitting Strings with String FunctionsUsing explode(), implode(), and join()Using strtok()Using substr()Comparing StringsPerforming String Ordering: strcmp(), strcasecmp(), and strnatcmp()Testing String Length with strlen()Matching and Replacing Substrings with String FunctionsFinding Strings in Strings: strstr(), strchr(), strrchr(), and stristr()Finding the Position of a Substring: strpos() and strrpos()Replacing Substrings: str_replace() and substr_replace()Introducing Regular ExpressionsThe BasicsDelimitersCharacter Classes and TypesRepetitionSubexpressionsCounted SubexpressionsAnchoring to the Beginning or End of a StringBranchingMatching Literal Special CharactersReviewing Meta CharactersEscape SequencesBackreferencesAssertionsPutting It All Together for the Smart FormFinding Substrings with Regular ExpressionsReplacing Substrings with Regular ExpressionsSplitting Strings with Regular ExpressionsFurther ReadingNext