PHP-Tutorials: Data types and conversion

Data Types 

PHP sports a cool feature called automatic data typing. A PHP developer can claim variables and use them in most common situations without having to claim the data type that the variable is. But this is also a double edged sword because as a developer gets more advanced they may create functions or scripts that only accept one data type, and throw errors if you feed it a different type. But that is usually only in the most complex of PHP applications.

PHP Tutorials- Variables,Constant

Global Variables

Global variables are set by a PHP script author to assure that a variable and its value will be available inside of a function, or when another PHP file is called to manipulate that variable. When you create custom variables in the normal fashion those variables and their values will not be available to you inside of a function or an externally called file. To make sure they are available you create the variable in the normal way and then apply the following code to make global and available to cover more scope only when needed.

PHP , Tutorials