Is there a max number of arguments JavaScript functions can accept?

Question

I know that JavaScript functions can accept "any" number of arguments.

function f(){};
f(1,2,3,4 /*...*/);

But I'm wondering if there is actually a limit to how many "any" can be?

E.g., let's say I hand a million arguments to f(). Would that work? Or would the interpreter keel over?

I'm guessing the maximum is either (a) implementation-specific or (b) (2^32)-1, since the arguments object is array-like.

I don't see this mentioned in the language specification, but I might not be connecting some dots.

Answer 1

Although there is nothing specific limiting the theoretical maximum number of arguments in the spec (as thefortheye's answer points out). There are of course practical limits. These limits are entirely implementation dependent and most likely, will also depend exactly on how you're calling the function.

---

I created this fiddle as an experiment.

function testArgs() {
    console.log(arguments.length);
}

var argLen = 0;
for (var i = 1; i < 32; i++) {
    argLen = (argLen << 1) + 1;
    testArgs.apply(null, new Array(argLen));
}

Here are my results:

• Chrome 33.0.1750.154 m: The last successful test was 65535 arguments. After that it failed with:

  Uncaught RangeError: Maximum call stack size exceeded

• Firefox 27.0.1: The last successful test was 262143 arguments. After that it failed with:

  RangeError: arguments array passed to Function.prototype.apply is too large

• Internet Explorer 11: The last successful test was 131071 arguments. After that it failed with:

  RangeError: SCRIPT28: Out of stack space

• Opera 12.17: The last successful test was 1048576 arguments. After that it failed with:

  Error: Function.prototype.apply: argArray is too large

Of course, there may be other factors at play here and you may have different results.

---

And here is an alternate fiddle created using eval. Again, you may get different results.

• Chrome 33.0.1750.154 m: The last successful test was 32767 arguments. After that it failed with:

  Uncaught SyntaxError: Too many arguments in function call (only 32766 allowed)

  ^{This one is particularly interesting because Chrome itself seems to be confused about how many arguments are actually allowed.}

• Firefox 27.0.1: The last successful test was 32767 arguments. After that it failed with:

  script too large

• Internet Explorer 11: The last successful test was 32767 arguments. After that it failed with:

  RangeError: SCRIPT7: Out of memory

• Opera 12.17: The last successful test was 4194303 arguments. After that it failed with:

  Out of memory; script terminated.