Replace string if specific characters found in php

Replace string if specific characters found in php

References

Reference NO 1

http://stackoverflow.com/questions/15199942/replace-string-if-specific-characters-found-in-php

Reference NO 2

http://php.net/manual/en/function.str-replace.php

Reference NO 3

http://www.w3schools.com/php/func_string_str_replace.asp

Reference NO 4

http://www.developphp.com/view_lesson.php?v=395

Reference NO 5

http://www.tuxradar.com/practicalphp/4/7/5

Reference NO 6

http://www.sitepoint.com/forums/showthread.php?484806-How-to-check-whether-a-character-exists-in-a-string

Reference NO 7

http://www.phpro.org/tutorials/Introduction-to-PHP-Regex.html

Reference NO 8

http://www.tutorialspoint.com/php/php_regular_expression.htm