Each of these assumptions should be documented and followed up at a later date to validate the scope. When you want to use global constants across PHP files, I feel a good practice is to use Object Oriented principles and define these in relevant classes. In order to define the scope, there will be assumptions that need to be made.

In contrast to local variables, a global variable can be accessed in any part of the program.

So yes, if you define something inside the if statement or inside the block, then it will be available just as if you defined it outside (assuming, of course, the code inside the block or inside the if statement gets to run).

You could only use this from within a class. “Scope” Means “That’s a Fact!” (Originated From Vancouver at PA) A Scope is a term used to describe a person who was once referred to as a spastic. Global Variables.
Define the Scope. PHP is a popular general-purpose scripting language that is especially suited to web development. Since get_defined_vars() only gets the variables at the point you call the function, there is a simple way to get the variables defined within the current scope.

PHP variables can be one of four scope types − Local variables; Function parameters; Global variables; Static variables. In PHP 7, array values are also accepted." There is no point in waiting until everything is clear to define scope. But prior PHP 7, you can maybe do this, to pass an array elsewhere using define:

The scope of a project typically consists of a set of deliverables, an assigned budget, and an expected closure time. 2.

The previously collected project requirements will help you define the scope.

If you try to define FOOTER_CONTENT a second time, php will throw a notice about it – Dale Nov 23 '12 at 14:06 I needed to calculate the current unix epoch time each time a page is loaded, then use that value in a couple calculations (functions). A variable name cannot start with a number. "define" worked for me. Be sure to write down exactly what the project will entail and what it will not entail. PHP originally stood for Personal Home Page, but it now stands for the recursive initialism PHP: Hypertext Preprocessor. Php 7 - Define: "Defines a named constant at runtime. These are the following rules for naming a PHP variable: All variables in PHP start with a $ sign, followed by the name of the variable.
Using the spl_autoload_register() function built into PHP, you can define all your later classes to extend the related "globals class" without worrying about including files manually everywhere. Definition and Usage.

PHP is the most required skill in current web development industry, the people who want to design their own website using PHP language should learn PHP certification. By that time, the project will probably be finished.
Constants are much like variables, except for the following differences: A constant's value cannot be changed after it is set; Constant names do not need a leading dollar sign ($) Constants can be accessed regardless of scope; Constant values can only be strings and numbers It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1994; the PHP reference implementation is now produced by The PHP Group. Scope can be defined as the range of availability a variable has to the program in which it is declared. A variable name must start with a letter or the underscore character _.