Write a PHP script to do the following: Use regular expression to remove all characters from a string except a-z A-Z 0-9 or " ". Sample string : ab9cde$dd3d @abcd )der] Expected Result : ab9cdedd3d...

Write a PHP script to do the following:

1. 
   
   Use regular expression to remove all characters from a string except a-z A-Z 0-9 or " ".

           Sample string : ab9cde$dd3d @abcd )der]

           Expected Result : ab9cdedd3d abcd der

      2 .  Use regular expression to check whether a string “I like a PHP     language “ contains PHP                    string  or not.