Hi,
Here's some code from pdf.js:
function stringToArray(str) {
var length = str.length;
var array = [];
for (var i = 0; i < length; ++i) {
array[i] = str.charCodeAt(i);
}
return array;
}
This kind of code shows up in a number of places in pdf.js. Pretty
simple -- filling in an array one element at a time.
Underneath the covers, this causes the array to repeatedly double in
size, which is annoying. And I thought I could avoid it because we
know how big the array will be in advance. So I changed the 3rd line
to this:
var array = new Array(length);
but I still get the same sort of doubling behaviour under the covers.
So then I tried reverting that change and inserting this line just
before the loop:
array[length - 1] = 0;
And now it avoids the doubling allocations -- the array elements are
allocated once, at the right size. But it feels dirty, and I don't
know if would give the same behaviour in other JS engines.
Is there a "right way" to do this?
Nick
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