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JavaScript

Posted by Patrick McKinney
Patrick McKinney
13,151 Points

Access to variables in other script files?

It seemed that at at one point in the video he said using these techniques provides a way to access a variable from another script file in the script file you are working with.

Am I correct in that understanding?

For example,

Let's say in the main.js file, there is a variable called map. And map has a loaded option (map.loaded). You could use the techniques he showed to gain access to map and map.loaded in a separate script file called customize.js?

Leonard Theisen
Leonard Theisen
16,518 Points

From my understanding once you've 'loaded' the .js file(s) they can all be accessed. The functions and global variables in each file is treated as if it's in the main page.

whether the javascript is in the .html file or a .js file, or multiple .js file it all works the same once the page as been loaded or accessed.

2 Answers

Jeremy Castanza
Jeremy Castanza
12,081 Points
Jeremy Castanza
Jeremy Castanza
12,081 Points

You're referring to a concept in programming called "variable scope." Here's a really good article on Javascript variable scope that should answer your question in simple terms. http://www.w3schools.com/js/js_scope.asp

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

Global variables should be accessible from anywhere in the program, no matter what file they are defined in.

Another way of sharing variables (and methods) is via "dependency injection". This is where an object containing resources (variables and/or methods) is passed as a parameter to a function, which then has access to them.