Strange behaviour of conditions in PHP

Strange behaviour of conditions in PHP

References

Reference NO 1

http://stackoverflow.com/questions/13585115/strange-behaviour-of-conditions-in-php

Reference NO 2

http://stackoverflow.com/questions/8632829/strange-behavior-with-php-empty-and-0-vs-0

Reference NO 3

http://stackoverflow.com/questions/16717732/unknown-wrong-behavior-in-php-if-statement

Reference NO 4

http://forum.xbmc.org/showthread.php?tid=162948

Reference NO 5

https://drupal.org/node/1999348

Reference NO 6

http://www.yiiframework.com/forum/index.php/topic/33698-strange-behaviours-with-conditions-where-int-in-cactivedataprovider/

Reference NO 7

http://codewiz.biz/article/post/php%20common%20errors%20and%20strange%20behaviours

Reference NO 8

http://php.net/manual/en/language.references.return.php