PHP is a Hypertext Preprocessor. This essentially means that PHP dynamically writes web pages for you. So it can query a database and print a report from it, or change CSS and such based on specific criteria.
Since Variables in PHP do not need to be declared you can run into issues such as trying to add a String to an Int. You also may have issues if you misspell a variable. […]
Do While Loops perform one iteration before a condition is tested.