Javascript variable undefined in IE until console displayed

Question

I have a small piece of code for a template project I'm working on. There are three separate buttons, that point to three separate locations. In order to make it easier for content providers, I have these buttons calling minimal routines to load the next page.

The code is as follows:

    /* navigation functions here for clarity and ease of editing if needed */
    prevURL    = 'ch0-2.html';
    nextURL    = 'ch2-1.html';
    manURL     = 'ch1-2.html';

    function prevPage() {
       window.location = prevURL; 
    }

    function nextPage() {
        window.location = nextURL;
    }

    function goManager() {
        window.location = manURL;
    }

This works perfectly in Firefox and Chrome, but seems to fail in Internet Explorer.

I open up the developer tools in IE (F12) and am presented with the message:

SCRIPT5009: 'manURL' is undefined

The location information (line 43, character 13) points to the "window.location = manURL" part of the code.

However, once the developer tools are open, if I hit F5 to reload the page, the button works without error until I close IE and reopen it, where it once again fails to respond and gives the same "undefined" error.

I'm baffled. Anyone have any ideas?

UPDATE I know the variable declaration is poor, and that I can use window.location.href instead. What is relevant here is that the other two pieces of code, which are identical in all of these significant ways, work perfectly either way.

epascarello has put me on the right track. by removing all console.log commands, everything starts working. I'm just wondering why this happens, and would like to be able to give epascarello credit for helping me.

The code you pasted above does not have 43 lines... so there is probably something happening before the declaration of manURL. — Iwan, Mar 06 '13 at 18:43
That's the only javascript in the page so far. the rest is html before that which loads CSS and the like. — FlippySquirrel, Mar 06 '13 at 18:45
Yes, there are two beforehand! I commented it out, and suddenly, everything started working. Can you explain to me what the heck happened? — FlippySquirrel, Mar 06 '13 at 18:49
Refactor your code. You are declaring variables in a very bad way. IE is not as clever as the rest and will fall on it's head — Dogoku, Mar 06 '13 at 18:50
@FlippySquirrel The reason IE bombs out without having the developer tools open is because by default the console is "not defined" in IE. — Iwan, Mar 06 '13 at 19:12
Thanks, Iwan. I hate IE with the heat of a thousand suns, and this further enhances my rage. — FlippySquirrel, Mar 06 '13 at 19:16

score 2 · Accepted Answer · answered Mar 06 '13 at 19:28

IE does not have console commands when the developer window is not open. So if you have them in there the code will not run. It will error out.

You can either comment out the lines or add in some code that adds what is missing.

if (typeof console === "undefined") {
   console = {
       log : function(){},
       info : function(){},
       error : function(){}
       //add any others you are using
   }
}

score 1 · Answer 2 · answered Mar 06 '13 at 18:50

1

Try setting

window.location.href

instead of just window.location.

Source: http://www.webdeveloper.com/forum/showthread.php?105181-Difference-between-window.location-and-window.location.href

answered Mar 06 '13 at 18:50

Everett Green

632
3
8

score 0 · Answer 3 · edited May 23 '17 at 11:49

Always define variables before using them ,being explicit (expressing the intention) is a good practice,

so define your variables like this,

var prevURL    = 'http://google.com';
var nextURL    = 'http://msn.com';
var manURL     = 'http://stackoverflow.com';

You can try using

window.location.href

refer to this post for difference

Suggestion: Make a jsfiddle.net for us so we could guide you easily

Javascript variable undefined in IE until console displayed

3 Answers3