A comment is the portion of a program that exists only for the human reader and stripped out before displaying the programs result. There are two commenting formats in PHP −

Single-line comments − They are generally used for short explanations or notes relevant to the local code. Here are the examples of single line comments.

<?

   # This is a comment, and

   # This is the second line of the comment

   // This is a comment too. Each style comments only

   print "An example with single line comments";

?>

Multi-lines printing − Here are the examples to print multiple lines in a single print statement −

<?

   # First Example

   print <<<END

   This uses the "here document" syntax to output

   multiple lines with $variable interpolation. Note

   that the here document terminator must appear on a

   line with just a semicolon no extra whitespace!

   END;

   # Second Example

   print "This spans

   multiple lines. The newlines will be

   output as well";

?>

Multi-lines comments − They are generally used to provide pseudocode algorithms and more detailed explanations when necessary. The multiline style of commenting is the same as in C. Here are the example of multi lines comments.

<?

   /* This is a comment with multiline

      Purpose: Multiline Comments Demo

      Subject: PHP

   */

   print "An example with multi line comments";

?>