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.
Commas before conjunctions (e.g., and, or, but). When a word like and, or, and but (called conjunctions) joins two standalone sentences, you should put a comma before it.(The real name for a standalone sentence within a longer sentence is independent clause .).Words like and, or, and but are known as conjunctions.SE A SEMICOLON. When indepedent clauses containing commas are merged together using a conjunction, it is possible to use a semicolon instead of a comma before the conjunction. However, this is quite an outdated practice in modern writing.