Javascript function call context

Question

I have this situation:

A JavaScript function A(){} and anotherfunction B(){}.

I call function A in two modes:

Is there a way to sense in code when function A is evaluated as parameter and when is executed as standalone?

No, there is no way to do that. Why would you want to do that? What problem would that solve for you? If you describe that problem, you're much more likely to get a useful answer. — Pointy
– Pointy, Commented May 19, 2013 at 17:40

DougM · Accepted Answer · 2013-05-19 17:43:30Z

3

Is there a way to sense in code when function A is evaluated as parameter and when is executed as a standalone?

No, because that's not what's happening. The following two code blocks are more or less identical, barring the tiny bit of extra memory for the var

function Implied() {
    B(A());
}

and

function Explicit() {
    var retA = A();
    B(retA);
}

In both cases, A is being called from the parent function, and not by B.

answered May 19, 2013 at 17:43

DougM

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Comments

Brad · Accepted Answer · 2013-05-19 17:43:28Z

0

I'm not sure why you would want to do that, but you do have a couple options.

One is to simply pass other parameters. This is what you probably should be doing.

Another option is to use call() or apply() to set the value of this.

function B() {
    var context = 'some value';
    A.call(context);  // `this` inside of A will be set to the value of context
}

answered May 19, 2013 at 17:43

Brad

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