Can I access variables from another file?

Is it possible to use a variable in a file called first.js inside another file called second.js?

first.js contains a variable called colorcodes.

Solution 1:

As Fermin said, a variable in the global scope should be accessible to all scripts loaded after it is declared. You could also use a property of window or (in the global scope) this to get the same effect.

// first.js
var colorCodes = {
  back  : "#fff",
  front : "#888",
  side  : "#369"
};

... in another file ...

// second.js
alert(colorCodes.back); // alerts `#fff`

... in your html file ...

<script type="text/javascript" src="first.js"></script> 
<script type="text/javascript" src="second.js"></script> 

Solution 2:

You can export the variable from first file using export.

//first.js
const colorCode = {
    black: "#000",
    white: "#fff"
};
export { colorCode };

Then, import the variable in second file using import.

//second.js
import { colorCode } from './first.js'

export - MDN

Solution 3:

I did like what answer above said but although, it didn't worked with me

because I was declaring these variables inside JQuery $( document ).ready()

so make sure you declare your variables inside the <script> tag not somewhere else

Solution 4:

Using Node.js you can export the variable via module.

//first.js
const colorCode = {
    black: "#000",
    white: "#fff"
};
module.exports = { colorCode };

Then, import the module/variable in second file using require.

//second.js
const { colorCode } = require('./first.js')

You can use the import and export aproach from ES6 using Webpack/Babel, but in Node.js you need to enable a flag, and uses the .mjs extension.

Solution 5:

This should work - define a global variable in firstfile and access it from secondfile:

<script src="/firstfile.js"></script>
<script src="/secondfile.js"></script>

firstfile.js:

var colors = {
   text:'#000000',
   background:'#aaaaaa',
   something_else:'blue'
};

secondfile.js:

do_something_with(colors.background);

Note that the order in which you load the script files is significant for some browsers (IE6 for sure, maybe others)