When comparing PHP vs C#, the Slant community recommends PHP for most people. In the question“ What are the best languages for backend in web development?” PHP is ranked 12th while C# is ranked 19th. The most important reason people chose PHP is:
According to the [2015 Stack Overflow Developer Survey](http://stackoverflow.com/research/developer-survey-2015#tech) (26,086 people surveyed), PHP was the 5th most popular/used language at 29.7%.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro One of the most common languages
According to the 2015 Stack Overflow Developer Survey (26,086 people surveyed), PHP was the 5th most popular/used language at 29.7%.
Pro Lots of tutorials online
Pro Used by most common CMS platforms
Many clients are looking for an easy-to-update web site that's flexible and free. Drupal and Wordpress fill those needs very well.
Pro Most prominent language for web applications
Part of the de facto standard web application stack.
Pro Great third-party package manager
PHP standard library is somewhat subpar, but if you need plugins, language features, composer has them all( you can even puzzle together a custom framework from composer).
Pro Fast
Since 7.x was released, PHP has become a pretty fast language.
Pro Lots of PHP frameworks available which help with development
PHP people love frameworks, and with frameworks such as Laravel, you can build a web app or API really fast (Facades, ORMs, scaffolding etc.)
Pro Great documentation
Pro Versatile
.NET offers rich functionality.
Pro Visual Studio
The Visual Studio IDE offers one of the best development environments. The Community Edition and Visual Studio Code can be used for free.
Pro Forms
Can be designed visually with the Visual Studio designer for traditional Windows forms, WPF, or Web forms.
Pro 3rd Party support
Lot's of tools and libraries available.
Pro Can be used in a variety of fields
With Xamarin for Mobile (ios, android),
with .net core asp for server (linux, windows),
with .net core for desktop (windows, mac),
with mono for desktop (windows, linux),
with blazor for web client with webassembly.
However, it is not considered top for any of those categories, but it is top choice for Windows desktop with .net framework and top choice for Unity.
.net 5 will unify frameworks similar to JVM (just one).
Pro Cross-Platform
Runs on Linux, Mac, and Windows.
Pro Supported By Microsoft
Constant updates and bug fixes to many popular frameworks, as well as great first-party support from Microsoft. This can be a con as well in certain circumstances.
Pro It is a C like language
Being a C like language counts in favor for it as a general purpose programming language, given the ease of using existing skills to pick up this language easily.
There are other superior languages that could be used as a general purpose, such as: F#, Haskell, but the complexity of those languages, being functional, make them strange to the usual C Syntax.
C# is better than C whenever garbage collection, Objects, classes, data access, are needed. But C is going to be the choice when hardware access and performance are paramount.
Cons
Con Poorly designed language
Despite its widespread use, PHP is generally looked upon poorly from a design point of view. The consistency of function names and function argument order, lazily and borderline non-functional implementation of object oriented programming, can only receive requests via POST methods, slow version adoption (the PHP you learn right now may not work on every webserver you'll work on), and a focus on "hacking things together" rather than "doing it right". These are all very common complaints when it comes to working with PHP. While not a bad language to learn, PHP is not at all a good language to learn first, as it will probably teach bad habits.
Con Immense catalog of insecure frameworks
The most serious security problems in websites on the web today are almost universally found in popular PHP frameworks, CMS platforms, libraries and code samples, almost all stemming from poor language design, bad tutorials and awful resources.
Con After python, probably one of the worst languages ever
Con Poorly designed language, awful syntax & luckily on the decline
Nobody in their right mind is using PHP for new software, if you decide to learn it as your first language you'll be stuck working in teams with old developers who have had no interest in the computer programming field since they landed their first job while maintaining some 2000 era archaic website codebase.
Con Most tutorials are out of date
A lot of very bad tutorials are still widely circulated among beginners, and these tutorials teach very poor programming practices.
Con Most resources are poorly-written
Few resources exemplify the "correct" or secure use of features.
Con Interpreter being too permissive
If you forget the dollar sign, the variable name will be converted to a string.
Con Learning curve
For a beginner the .NET framework can be daunting, the rich functionality means that things often can be done in several ways.
Con Very large runtime
Cannot be used for embedded programming.
Con Microsoft will mess up with the Visual studio installation
And all of a sudden you'll need to reinstall the entire thing just because it stopped working.
Microsoft assumes that every workstation is connected to the Internet then it is always pushing updates.
Con .NET is a mess
Troublesome in regards to being Microsoft centric, updates, security, excessively large, cross-platform issues, etc...
Con Windows OS centric
Not very good at being a cross-platform programming language.
Con Strictly object oriented
Con Owned by Microsoft
And like always, Microsoft is to be avoided, no exceptions.