Acodemy - PHP: Learn PHP In A DAY! : The Ultimate Crash Course to Learning the Basics of the PHP In No Time

Unlike many other languages, PHP does not require you to explicitly declare the variable type, rather, it determines it from the context. In other words, you dont have to explicitly tell PHP whether you want a variable to be a double precision number or a string. To help you imagine this, you can think of variables as boxes. Imagine a row of lockers (like the kind you would see at an airport or a train station). Each locker represents a variable. Each locker has its own unique number, which differentiates it from all of the other lockers. If someone tells you to open locker number 42, you would be able to find it without a problem and you wouldnt confuse it with any other locker (for example 24). In a similar way, PHP variable names are unique and each PHP variable is unique. Now, you open locker number 42, and you see that it is empty. You move on to locker 43 and see that there is a package inside it. You take the package from 43 and place it in 42. Before opening the lockers you didnt know what was in the lockers. After checking, you know what is contained inside that locker and you can manipulate it as desired. In a similar fashion, variables in PHP can contain anything you place in them. Essentially, when you are checking the type of a variable, you are checking the type of the content inside of the variable.