CONSTANTS and PHP Class Definitions. Using define('MY_VAR', 'default value'). INSIDE a class definition does not work as expected. You have to use the PHP keyword 'const' and initialize it with a scalar value -- boolean, int, float, string (or array in PHP 5.6+) -- right away.
Prepositional Phrases. Do not use a comma between separate phrases unless they are in a series. A comma may also set off a single prepositional phrase at the beginning to make the sentence clear. A comma is recommended after any introductory prepositional phrase of more than four words. Correct: Under the kitchen table the dog cowered. (Single short, clear phrase.
Use one comma before to indicate the beginning of the pause and one at the end to indicate the end of the pause. 4. Do not use commas to set off essential elements of the sentence, such as clauses beginning with that (relative clauses). That clauses after nouns are always essential. That clauses following a verb expressing mental action are always essential.