Role of C++/JavaScript in QML language ?

[Code Man]

Hi , every one
I found in Wiki that QML language is written in C++ / JavaScript.
I want to know what the role of each language (C++,JavaScript ) in QML. development?
In other words, which part is coded in C++ ? and which in JavaScript?

Thanks :-)

[sierdzio]

The QML engine itself is written in C++. It contains a JS parser and compiler (v4), so that when you use JavaScript inside QML files, they will run.

[Code Man]

Thanks , sierdzio :-) .