What language are inbuilt PHP functions written in?

Question

This may sound like a stupid question but I\'m a beginner not just to PHP but to programming in general, so in that context:

What language are inbuilt PHP functions writ

Answer 1

PHP has been written in what I call the mother of languages ^C^

Answer 2

PHP was written in C. Any language above machine code for the specific processor architecture is written in a lower-level language. These abstractions into higher-level languages are an effort to make programming simpler and more productive.

Answer 3

PHP is in C, parts of it and some of is extension are written in C++.

Answer 4

You can see it's source code on GitHub - https://github.com/php/php-src