This question have simple answer i.e. No.
Because WordPress is complete CMS and can use WordPress without writing a single line of code in PHP and Without coding in WordPress you can create beautiful blog, beautiful Website, Beautiful Shopping Website.
You can customize WordPress by adding Themes and plugin.
First you should know What is PHP ?
According to Wikipedia
“PHP is a server-side scripting language designed for web development but also used as a general-purpose programming language”
PHP code embedded into HTML code and it is processed by PHP interpreter.
Example of PHP Code:
echo “Hello, Sparkling Talk”;
How should this achieve?
To build website or blog without coding you need plugin and themes. There are more than thousand WordPress themes and
plugin. Both plugin and theme just need to install in WordPress and use it.
You need to know PHP When required to change function or complete hack of WordPress function.
With the knowledge of PHP you can develop your own theme according to your requirement.
you can also create or modified WordPress plugin with the knowledge of PHP.
WordPress build with PHP programming language but to customize WordPress you don’t need to know PHP but To changing function or developing theme/ plugin you should know PHP.