i am also new to development. i know html , css but not much knowlwedge in javascript. Is it must to know javascript to learn google dart. pls advice.

If you learn Dart, you should also learn JavaScript, HTML, and CSS. Dart is a good place to start because of its bundled libraries and editor.

I think two biggest differences are:

1) Dart is not just syntax upgrade from JS unlike TypeScript.
2) Dart works great on the server (maybe it’s possible to run TS too but I doubt it was meant for that..)

to elaborate on John’s superset point, TypeScript s just syntactic sugar for JavaScript that provides a more traditional OO approach to JavaScript that most .Net/Java guys are accustomed to and thats it.

Dart on the other hand not only brings OO features to the table but as the Dart team likes to say it comes with “batteries included” i.e. it has libraries that support html, IO, isolates (i.e. threading), templating, data-binding, web components, etc etc.

I see Dart as the new “.Net” of the web whereas TypeScript is just syntactic sugared version of JavaScript.

I agree with what you said in the current web environment, but I believe Google has big plans with Dart and Blink. Think about what happens when the Dart VM is baked into Blink and other browser vendors quit using the dead webkit branch and move over to Blink. Suddenly, a majority of browsers support Dart VM out of the box. If this happens, the speed of Dart will make it a competitive advantage to use, and there would be no sacrifice in portability, because no Dart VM browsers could just use the JavaScript translated version.
So, I think that the reason someone would want to user Dart today is because at the very least it makes it easier to write an application that is heavy on client side scripting, which will work even without a Dart VM. The Dart language is a big improvement over JavaScript, IMO.

Thanks for the encouragement on the podcast and
YouTube videos. I am enjoying doing these! 🙂

I agree with #1 except for the fact that in order to make it portable, you have to explicitly compile to JS. As for #2, I would imagine the reason why it’s fast it’s because the VM is tightly coupled to Chrome. It kind of reminds me of Java Applets which require a VM. However, I would bet that as the web paradigms progress and with ECMA Script 5, the engines for JS will be also 8X faster natively.
What would you save are the best use-cases for wanting to use Dart for an Enterprise/Commercial application?
BTW, I enjoy your workout/career tips. Keep it up!

Great question.
In my opinion it comes down to 2 main things.
1. Dart is a independent language that can be compiled down to JavaScript, but doesn’t have to. TypeScript is a superset of JavaScript, which greatly restricts it’s development and usage. As a good example of why, in general, I don’t like superset languages, take a look at Objective-C, a superset of C.
2. Dart is fast! Very very fast. Like 8x the speed of the fastest JavaScript engine. Dart isn’t even optimized yet. In my mind, this is huge!