问题
Looking into javascript types I'm trying to find out what the maximum storage size for some data types are. For instance, I set up a quick recursive algo to increase var size till the browser crashes, which ends up being somewhere close to 128mb (or maybe it's 256) for strings on my existing version of chrome.
I've been doing it the painful way because I couldn't find any specs on this, but constant browser crashes make this a painful trial (try catch seems useless for some reason with this particular issue).
I'm looking for information about maximum storage size for the other types also (array, object, functions, strings, numbers, bools...)
EMCA-262 section 8.4 is vague on this
The length of a String is the number of elements (i.e., 16-bit values) within it. The empty String has length zero and therefore contains no elements.
...so perhaps this is something that needs to be identified as implemented in browsers?
ECMA does however tell us about numbers, for example,
The Number type has exactly 18437736874454810627 (that is, 2^64−2^53+3) values, representing the double-precision 64-bit format IEEE 754 values as specified in the IEEE Standard for Binary Floating-Point Arithmetic, except that the 9007199254740990 (that is, 2^53−2) distinct “Not-a-Number” values of the IEEE Standard are represented in ECMAScript as a single special NaN value.
But then I don't see anything about objects.
What can I expect for use in browsers? Is there any code-base out there that helps manage very large objects and strings?
How much memory can I allocate in a single script?
回答1:
As you already stated, the specification does not state any size limits / requirements for types besides Number.
So this is definitally left to the implementation.
For example, Chrome's limit on strings seems to be hard coded at around 512mb (and less on 32bit).
This puts a limit on the maximally possible allocation request in 32-bit versions of 2^27-1. The maximal flat string length is ~2^28 (512MB space), and the maximal string length is 2^29-1, so neither of these limits catch the problem (we would throw an Out-Of-Memory exception instead if they did).
See: http://code.google.com/p/v8/issues/detail?id=362#c9
As far as the other browsers go, this would need some research e.g. looking into Firefox's code. But I doubt we can do the same for IE / Opera.
回答2:
ECMA section 6.1.4 is explicit about this.
"The String type is the set of all ordered sequences of zero or more 16-bit unsigned integer values (“elements”) up to a maximum length of 2^53-1 elements"
回答3:
I have listed some typical limits for strings in another answer. Basically, you are in safe territory up to a string length of 227 characters.
来源：https://stackoverflow.com/questions/4695187/javascript-maximum-size-for-types