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#! usr/local/bin/perl5

# file four

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print "Here are three colors: Red, White, Blue\n";

print "Guess which one is special\n";

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$guess = <STDIN>;

print "You guessed $guess\n";

 

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if ($guess =~ /\bred\b/i)

 

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    {print "That is right!\n";}

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 else

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     {print "That is wrong\n";}

 

 

Comments:

            /red/

            This is a pattern of characters to be searched for in a string.  Regular expressions are enclosed in slashes.

            \b

            A word-boundary pattern anchor.

                        /\bdog/ matches only those words beginning with dog

                                    “dogfood” =~ /\bdog/  true

                        /dog\b/ matches only those words ending with dog

                                    “hotdog” =~ /dog\b/    true

                        /\bdog\b/ matches only those words beginning and ending with dog

 

            /i

            A pattern matching option ignoring upper and lower case.         

 

($guess =~ /\bred\b/i)

                Evaluates to true if $guess is a word that begins with red, ends with red, regardless of upper and lower case.