javascript，奇怪的功能安排，不明白

Question

See the below javascript. When functions are arrangment this way, how is it that they are able to run without being called specifically. What I mean is that the function below runs without being called and I don't understand how.

(j, function() {
alert(1);
})

it is eval'd like this:

eval(s)(j, function() { catch (_) { } } 

Answer 1

It looks like those are the arguments to a function call, ie

foo(j, function() {
   alert(1);
})

That will pass the current value of j as the first argument, and the function listed there as the second argument.

That said, in order for that function—the one that alerts 1—to be called, foo would have to manually call it. Something along the lines of

function foo(j, f){
    f();
}

---

EDIT

So, per your question edit, it looks like what's above is more of less correct, except instead of referencing the function directly, you're fetching it from an eval statement.

Something like this:

function foo(j, f){
     f();
}
var s = "foo";
var j = 0;
eval(s)(j, function() {
    alert(1);
})

Here's a working FIDDLE