Javascript function's property that contains its code

Question

I am new to Javascript. I did a course sometime back and I am trying to remember a concept about that all the functions are objects that will contain a property that will contain the code written inside that function and another property that contains name of the function.

I tried that and I found name property like below. but not able to find the code property. Does that really exist or I may be wrong.

console.log(
 (function f() {
 a = 1
 }.name)
)

so the property should return

a=1

Not trying to do anything. I am brushing up my JS as I want to learn angular.

• user2263572: Here are a list of keys found on Functions object prototype. Probably what you need: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…
• Rajaprabhu Aravindasamy: Are you trying something like ({a:1}).a?

Answer 1

but not able to find the code property. Does that really exist or I may be wrong.

It exists conceptually, but it is an internal property, which cannot be accessed from user code. It's called [[ECMAScriptCode]]. See the spec for more details.

In reality though, browsers could implement functions in any way they want, as long as they behave as described in the spec.

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What you can do in user code is call the function's toString method. That will return a string representation of the function itself, though the exact representation is implementation dependent.

• Dexters: Thanks great link to the spec!

Answer 2

I believe you are looking for something like the following:

function f(){
 console.log("a = 1");
};
console.log(f.toSource());
console.log(f.toString());

https://jsfiddle.net/agraymd/ar5hgkv8/1/

.toSource is however not a standard feature. From the MDN:

This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

function.toSring(); seems to be a better alternative, which is a standard feature. More on that here:

.toString();

• Dexters: Yes tosource seems only for gecko engines

Answer 3

Try f.toString() where f is the function you wish to obtain the source code of.