double-indentation.md

Double-indentation

Avoid "double-indenting" blocks of code where no indentation is necessary for readability

The purpose of indenting code is to make it visually clear where a block of control starts and ends. With respect to using 80 character maximum line lengths, care should be taken to only indent blocks that actually increase readability.

Each indentation within code produces a new line of attention for the reader to keep track of while skimming your code. Aiming for less lines of attention produces more readable code.

Within this guide, only blocks that affect scope or control should be indented. Certain blocks, such as switch statements do not need to have double-indentation, because the contents of the blocks are within the same scope, and scope is perfectly obvious without indentation.

### Good example:

<?php
namespace Example\App;

class GoodExample {
	const EXAMPLE_CONSTANT_ONE = 1;
	const EXAMPLE_CONSTANT_TWO = TWO;
	private $spam;
	private $eggs;

	public function noNeedForIndentation(int $count):void {
		switch($count) {
		case EXAMPLE_CONSTANT_ONE:
			$this->doSomething();
			break;

		case EXAMPLE_CONSTANT_TWO:
			$this->doSomethingElse();
			break;
		}
	}
}

Within switch statements, it is easy to scan the eye down the code to see where each case starts, without having to indent the block again.

### Bad example (too many indents):

<?php
namespace Example\App;

class BadExample {

	const EXAMPLE_CONSTANT_ONE = 1;
	const EXAMPLE_CONSTANT_TWO = TWO;
	private $spam;
	private $eggs;

	public function noNeedForIndentation(int $count):void {
		switch($count) {
			case EXAMPLE_CONSTANT_ONE:
				$this->doSomething();
				break;

			case EXAMPLE_CONSTANT_TWO:
				$this->doSomethingElse();
				break;
		}
	}

}

As a follow on from this section of the guide, it is recommended to have a limit of four levels of indentation anyway.