---
title: "PHP switch best practices"
url: https://www.exakat.io/well-structured-switch-command-in-php/
date: 2023-10-04
modified: 2025-02-13
author: "dams"
description: "[caption id=\"attachment_14452\" align=\"alignleft\" width=\"282\"] switch best practices[/caption] Ensuring a Well-Structured Switch Command in PHP In PHP, the switch statement is a powerful tool for controlling program flow, especially when dealing..."
categories:
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tags:
  - "audit"
  - "suggestions"
  - "switch"
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---

# PHP switch best practices

[![switch best practices](https://www.exakat.io/wp-content/uploads/2023/10/oldphone.320-282x300.jpg)](https://www.exakat.io/wp-content/uploads/2023/10/oldphone.320.jpg)switch best practices

## Ensuring a Well-Structured Switch Command in PHP

In PHP, the `switch` statement is a powerful tool for controlling program flow, especially when dealing with multiple conditional branches. However, achieving a clean and efficient switch has its own snags. This post explores the essential switch best practices: tips for checking the quality of a 'switch' command to ensure code quality and optimize its performance.

## Missing Default Entry

The first aspect to consider is whether the `switch` statement includes a `default` case. A `default` acts as a fallback option, ensuring that the code executes when none of the defined `case` match.

`default` should always be present. In fact, the command `match`, which is an alternative version of `switch`, throws an exception when it cannot match any of the `case`, and the `default` is missing.

`default` serve different purposes :

- Handle all other cases as one. This is when a finite list of cases is available, and anything outside that list can be handled in a single manner.
- Raise an error if ever is it reached. In this situation, the context preceding the `switch` ensures that a finite list of cases is handled. Then, whenever a case outside the legit ones reach the command, an exception should be raised.

Always ensure that switch has a default.

## Duplicate Cases

It's rewarded to examine a `switch` statement for duplicate cases. PHP only process the first case that it encounters, ignoring the others. This leads to dead code, with some of the branches in the switch to be ignored and never used.

Duplicates happen often in very long list of cases.

They also happen when the actual value is hidden by constant names, or also, by PHP's type juggling. Indeed, `switch` uses a relaxed comparison style, and some literals may actually be the same.

Carefully review the cases values and remove the duplicates.

## Duplicate Code Blocks

Another common issue is the repetition of code blocks in different case branches. This redundancy can bloat your `switch` and make it challenging to update in the future. Consider refactoring your code to eliminate duplication and merge the cases.

## Usage of Enumeration Cases

PHP has built-in support for [enumerations](https://www.php.net/manual/en/language.types.enumerations.php). One of the important advantages of enumerations is their finite nature. They represent a full collection of options, and no other option shall exist. This makes it easy to check if a `switch` is covering all the possible situations.

## Optimization with Simple Switch

PHP 7.2 introduced an optimisation for `switch`, called [simple switch](https://php-dictionary.readthedocs.io/en/latest/dictionary/simple-switch.ini.html).

Until then, PHP would review each cases one after the other, and stop as soon as it finds a matching value. With PHP 7.2 and later, PHP sets up a lookup table for the case values, when they are simple literals. Then, PHP jumps immediately to the right case, and bypass all other non-matching cases.

Simple switch happens when all the cases are simple values, that can be directly compared to a incoming variable.

If the switch has a mix of expressions and simple values, it is recommended to separate the simple literals in a first `switch`, and put the others in a second switch.

It might also be more convenient to process them in a different manner, with a previous condition, for example.

## Switch() best practices

In conclusion, a well-structured `switch` statement in PHP can greatly enhance your code's clarity, maintainability, and performance. By checking for missing default entries, eliminating duplicate cases and code blocks, leveraging enumeration-like structures, and optimizing complex switches, you can ensure that your `switch` statements remain an efficient and effective part of any PHP codebase.

Happy PHP code auditing