Well, for one I did not learn to write scripts for InDesign by watching tutorials, or by reading Adobe’s documentation, or from some magical webpage where everything was spelled out for me. I learned it by doing it – for a decade. As programming languages go, Javascript is pretty well documented – and quite forgiving as well. Even if you feel you have written some very bad code, well, if it works, it works. And if it doesn’t, tinker until it does. Writing highly optimized code comes last. Writing pretty code may never come for some.
> … where should I look for DOM (if it is needed) etc …
Javascript is a programming language, and with it, you can write programs. However, it is just a programming language. There is no universal interface to other programs, so everything – yes, everything – you want to do “in” another program needs interacting with its DOM. You can write all the Javascript for a webpage you want, but if you never do a document.write(“Hello World!”);
, then how do you know it even did run – if you don’t interact with the HTML DOM to see the output?
> … MS Word or MS Excel etc, then who is going to help me, where will I find the milestone to get started …
How do you find anything on the web? Google. For example, I did not even know that one could write Javascript for MS Office programs (and I was going to say so) but hey! look! Google turned up this: https://msdn.microsoft.com/en-us/magazine/jj891051.aspx
But the bottom line is: there is no substitute for plain grunt level “learning”. As Kylie Minogue says, “There’s no shortcut to learning a craft; you just have to put the years in.”