Storing a variable in the JavaScript ‘window’ object is a proper way to use that object?

by

In JavaScript, any global variable is actually a property of the window object. Using one is equivalent to (and interchangeable with) using the other.

Using global variables is certainly “common,” so the question is whether or not it’s “proper.” Generally, global variables are discouraged, because they can be accessed from ANY function and you risk having multiple functions trying to read from and write to the same variables. (This is true with any programming language in any environment, not just JavaScript.)

Solve this problem by creating a namespace unique to your application. The easiest approach is to create a global object with a unique name, with your variables as properties of that object:

window.MyLib = {}; // global Object container; don't use var
MyLib.value = 1;
MyLib.increment = function() { MyLib.value++; }
MyLib.show = function() { alert(MyLib.value); }

MyLib.value=6;
MyLib.increment();
MyLib.show(); // alerts 7

Another approach is to use .data() to attach variables to a relevant DOM element. This is not practical in all cases, but it’s a good way to get variables that can be accessed globally without leaving them in the global namespace.

More Related Contents:

  1. How do I check if an element is hidden in jQuery?
  2. Why does jQuery or a DOM method such as getElementById not find the element?
  3. How do I set/unset a cookie with jQuery?
  4. jQuery .live() vs .on() method for adding a click event after loading dynamic html
  5. Detect element content changes with jQuery
  6. How can I select an element by name with jQuery?
  7. What is the most efficient way to create HTML elements using jQuery?
  8. Firing event on DOM attribute change
  9. jQuery object and DOM element
  10. How to expose IFrame’s DOM using jQuery?
  11. Finding line-wraps
  12. How to get the element clicked (for the whole document)?
  13. Check if option is selected with jQuery, if not select a default
  14. How to check if an embedded SVG document is loaded in an html page?
  15. How to show a spinner while loading an image via JavaScript
  16. How to move an iFrame in the DOM without losing its state?
  17. $(window).scrollTop() vs. $(document).scrollTop()
  18. How do I monitor the DOM for changes?
  19. Can I change an HTML element’s type?
  20. Difference between screen.availHeight and window.height()
  21. jQuery events .load(), .ready(), .unload()
  22. change html text from link with jquery
  23. Jquery Event Not Triggering for DOM Elements Created after page load [duplicate]
  24. How to dynamic filter options of with jQuery?
  25. How to stop event bubbling with jquery live?
  26. Why do multiple `.appendTo` calls on a newly created jQuery element only append it once?
  27. DOM Mutation event in JQuery or vanilla Javascript
  28. How to add DOM element script to head section?
  29. Best practice to avoid memory or performance issues related to binding a large number of DOM objects to a click event
  30. Removing element with jQuery?

Leave a Comment