For this practice we will use the preg_split function to do the following:

1. Split a sentence into a collection of words.

   For example:

   $sen = "This is a sentence";
   

   Could be processed into an array such that:

   $a[0] = "This";
   $a[1] = "is";
   $a[2] = "a";
   $a[3] = "sentence";
   

2. Split a sentence into a collection of characters.

   For example:

   $sen = "This is a sentence";
   

   Could be processed into an array such that:

   $a[0] = "T";
   $a[1] = "h";
   $a[2] = "i";
   $a[3] = "s";
   $a[4] = " ";
   $a[5] = "i";
   ...and so on...
   

3. Extract all of the arithmetic operators out of a mathematical expression.

   For example:

   $exp = "3 + 5 * 9 / 2";
   

   Could be processed into an array such that:

   $a[0] = "3";
   $a[1] = "5";
   $a[2] = "9";
   $a[3] = "2";
   

4. Separate the paths of a directory.

   For example, the variable $PHP_SELF has the following value for this page:

   In the above the path to the file is specified with "/" to represent each sub-directory. Process the above such that:

   $a[0] = "~jfulton";
   $a[1] = "php3";
   $a[2] = "practice11.php";
   

Remember to escape any characters that you use which have special meaning by using the backslash.

To complete this exercise you must:

• Create a file in "public_html/php" called "split.php".
• Be sure that "split.php" is viewable from the web.
• Fill in "split.php" with this incomplete code.

Your program should look like this when run.

HINT:
The Perl Compatible Regular Expression that allows you to represent whitespace (" ") is the following:

\s

The above symbol will be helpful for the first example.