<?php
	// (File names should be all lower case. Files should be in UTF-8 encoding.)
	// (Line endings should be Unix-style LF (\n, not \r\n).)

	// Class names capitalize each word and separate words with underscores:
	class My_Class
	{
	// <-- Indentation should be provided with tabs, not spaces

		// Constants should be written in ALL_UPPERCASE_WITH_UNDERSCORES:
		const DEFAULT_VALUE = 0;

		// Alignment should be provided with spaces and each variable
		// should be declared on its own line:
		protected $x = 5;
		protected $foo_bar = false; // <-- Variables should be in snake_case

		// Methods should always declare their visibility (public, protected, private)
		// and should be written in snake_case:
		public function is_zero($number)
		{
			$number = (int)$number; // Keywords (int, array, etc) should be lowercase

			// Control flow structures should provide a space between the keyword
			// and arguments (if, for, foreach, while, switch):
			if ($number == 0)
			{
				// Keywords like true, false, null, etc should also be lowercase:
				return true;
			}

			return false;
		}

		public function get_term_id($semester)
		{ // <-- All braces should always be presented on their own line.
			$id = 0;

			switch ($semester)
			{
				// (Each case block is separated from each other by an empty line.)
				// Case statements are indented:
				case 'Fall 2012':
					$id = 1;
					break;

				case 'Spring 2013':
					$id = 2;
					break;
			}

			return $id;
		}

		public function do_something($number)
		{
			// ! should be surrounded by spaces:
			if ( ! $this->foo_bar)
			{
				// Provide spaces before and after logical and math operators:
				return $number + 5;
			}

			return 'hello'; // <-- Always single quote strings if possible
		}
	}

	// Braces for empty classes should be touching and should exist on the same line
	// as the class definition:
	class My_Empty_Class {}

	// <-- Closing ?> tag should be omitted