Here's a Python-like range() for JavaScript. Is it new?

Hello

Here's a Python-like range function that might be useful. I've not tested it for performance, but expect it to be quicker on large ranges, and no slower for small ones.

If anyone has seen this trick before, please do tell the newsgroup. And the same goes for bugs.

For arrays one can, of course, use the trick directly.
for (i in myArray){
value = myArray[i];
// do something.
}

I've found that in Firefox/SpiderMonkey adding to Array.prototype breaks the trick.

===
$ cat js/range.js

// Definition of range.
var _range;
// FF2, FF3
_range = '.....................................................';
// IE6
_range = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];

var range = function(n){
return _range.slice(0, n);
};


// Use of range.
var i;
var x = [];
for (i in range(11)){
x[i] = 10 - i;
};

print(x);

for (i in range(x.length)){
x[i] = i * i;
}

print(x);

$ js js/range.js
10,9,8,7,6,5,4,3,2,1,0
0,1,4,9,16,25,36,49,64,81,100
==

--
Jonathan
.

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