在另一个js文件中使用javascript函数

Question

i'm following along a book and I have 2 javascript files. Both are in the HTML file as:

<script src="playlist_store.js"></script>
<script src="playlist.js"></script>

however, when I try to call a function from playlist_store.js inside of playlist.js chrome debugger says "uncaught reference error. loadPlaylist is not defined. loadPlaylist() is the function from playlist_store.js

I thought there might be a typo somewhere but I don't think there is. Does playlist.js actually need to somehow import or include / require the playlist_store.js ? Is the browser not smart enough to somehow link them so the functions in one you can call from another?

Answer 1

Defining a function like follows

function myaction () { }

is a named (private) function.
It is better to write a (private) function assigned to a variable:

var myaction = function () { };

Now what you need is a function, that is assigned to a variable in the global object:

myaction = function () { };
// or strict:
window.myaction = function () { };

It is now a global (public) function, so you can use it outside of your defining .js.

Beware that the first example, a function statement doesn't have a semicolon. Using the function operator as in the other examples, you need a semicolon.