PHP in_array seeing if there is a better way to do this

PHP in_array seeing if there is a better way to do this

References

Reference NO 1

http://php.net/manual/en/function.in-array.php

Reference NO 2

http://stackoverflow.com/questions/11577046/php-in-array-best-way-to-check-an-array

Reference NO 3

http://stackoverflow.com/questions/6969638/php-in-array-isnt-finding-a-value-that-is-there

Reference NO 4

http://stackoverflow.com/questions/4128323/in-array-and-multidimensional-array

Reference NO 5

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

Reference NO 6

http://www.webmasterworld.com/php/4046733.htm

Reference NO 7

http://codereview.stackexchange.com/questions/25276/best-way-to-check-for-one-of-two-values-in-an-array-in-php

Reference NO 8

http://brian.moonspot.net/2008/06/05/in_array-is-quite-slow/