Get a variable that is inside a function

Question

I have this HTML document:

<!DOCTYPE html>
<html>
    <body>
        <script type="text/javascript" src="/first.js"></script>
        <script type="text/javascript" src="/second.js"></script>
    </body>
</html>

first.js:

(function(){
    var p = 9;
    ...
})();

How to have access and edit the p variable from second.js without modifying first.js? Is there a way?

You should see [this question](https://stackoverflow.com/questions/500431/what-is-the-scope-of-variables-in-javascript). — Serge K., Sep 05 '17 at 09:33

score 0 · Answer 1 · answered Sep 05 '17 at 09:32

0

You can make your variable global using :

(function(){
    window.p = 9;
    ...
})();

answered Sep 05 '17 at 09:32

Nolyurn

568
4
17

`without modifying first.js` – Jerodev Sep 05 '17 at 09:33
Is there a different way without modifying first.js? – ZTTR Sep 05 '17 at 09:35
There is no way, using `var` mean your variable exist only on the scope of the function first, you can't set it to global from outside the function, sorry. – Nolyurn Sep 05 '17 at 09:36

score 0 · Answer 2 · answered Sep 05 '17 at 09:32

0

Set p as global variable in first.js

var p;
(function(){
   p = 9;
    ...
})();

answered Sep 05 '17 at 09:32

Stéphane Ammar

1,454
10
17

Is there a different way without modifying first.js? – ZTTR Sep 05 '17 at 09:35

viola · Answer 3 · 2017-09-05T10:15:47.803

0

export your variable

(function(exports){
   exports.p = 9;
    ...
})(window);

edited Sep 05 '17 at 10:15

answered Sep 05 '17 at 09:40

viola

60
7

While this code snippet may solve the problem, it doesn't explain why or how it answers the question. Please include an explanation for your code, as that really helps to improve the quality of your post. Remember that you are answering the question for readers in the future, and those people might not know the reasons for your code suggestion – Prashant Tukadiya Sep 05 '17 at 10:10

Get a variable that is inside a function

3 Answers3