How to change a javascript variable?

Question

I'm trying to change a variable depending on what it's current value is:

window.addEventListener("popstate", function(e) {     
    if (direction === leftnav){
        direction = rightnav
    }
    else{
       direction = leftnav
    };

    loadPage(location.pathname);
});

this doesn't seem to work somehow :s can someone help me with this? Thanks in advance :)

EDIT: here is the full js file: http://pastebin.com/7zZseW74

EDIT 2: what seems to happen is that the loadPage function just does not seem to fire...

What "does not work"? What is the value of direction, leftnav and rightnav? Your example is too vague to be answerable... — Aron Rotteveel
– Aron Rotteveel, Commented Apr 3, 2011 at 13:10
basicaly, i add css differenly depending on the value of direction. Now i want to intercept a popstate event but invert the direction, so change the variable set earlier. — cmplieger
– cmplieger, Commented Apr 3, 2011 at 13:19
@Šime direction cathes the class of a parent element. If the class is leftnav it sets it to leftnav, if it is not it sets it to another class — cmplieger
– cmplieger, Commented Apr 3, 2011 at 13:41

Pablo Santa Cruz · Accepted Answer · 2011-04-03 13:19:39Z

1

Try using == instead of ===:

if (direction == leftnav) {
   direction = rightnav;
} else {
   direction = leftnav;
}

Also, do include proper ; inside if and else clauses. You could also provide more information in order to get better help. Information like: what are leftnav and rightnav variables. If they are not variables but literals, you should enclose them within ". Like "rightnav" and "leftnav".

edited Apr 3, 2011 at 13:19

answered Apr 3, 2011 at 13:11

Pablo Santa Cruz

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6 Comments

Olli Over a year ago

Actually, last ; is perfectly fine, it should be there. It's for window.addEventListener. Additionally, in Javascript you can have multiple ; without any problem (and missing ones for that matter; those are added automatically).

Pablo Santa Cruz Over a year ago

@Olli: Agree. But question was edited. I didn't have that information when I wrote the answer. :-)

Michael Krelin - hacker Over a year ago

I think he meant the one after if, not the very last one.

cmplieger Over a year ago

@pablo I tried both, it didn't work :(. I've included the full file in the main post now

Olli Over a year ago

Oh well, true. Still, little known fact, line breaks are enough, you don't have to use ;, and you can add additional ;'s without problem.

|

Lauw · Accepted Answer · 2011-04-03 13:10:06Z

0

if (direction == leftnav){

^ requires only 2 '=' signs.

should be correct for the rest.

answered Apr 3, 2011 at 13:10

Lauw

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Comments

dee-see · Accepted Answer · 2011-04-03 13:10:54Z

0

I believe all you're missing is semicolons.

if (direction == leftnav) {
    direction = rightnav;
} else {
    direction = leftnav;
}

Also, unnecessary ===

answered Apr 3, 2011 at 13:10

dee-see

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Comments

MoniR · Accepted Answer · 2011-04-03 13:11:33Z

0

try this

if (direction == 'leftnav')
    {direction = 'rightnav';}
else
    {direction = 'leftnav';}

answered Apr 3, 2011 at 13:11

MoniR

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Comments

Michael Krelin - hacker · Accepted Answer · 2011-04-03 13:20:49Z

0

You haven't said a thing about leftnav and rightnav variable, so I suspect that you may want to use strings ('leftnav' and 'rightnav') instead, otherwise both are likely to be undefineds.

EDIT: Now that you posted the code, brief look at it suggests that yes, you wanted quoted strings.

window.addEventListener("popstate", function(e) {
    direction = (direction=="leftnav")?"rightnav":"leftnav";
    loadPage(location.pathname);
});

edited Apr 3, 2011 at 13:20

answered Apr 3, 2011 at 13:12

Michael Krelin - hacker

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4 Comments

Michael Krelin - hacker Over a year ago

SnippetSpace, I couldn't find definitions. And I still can't.

cmplieger Over a year ago

direction = $(this).attr('class'); That happens before a popstate in any case

Michael Krelin - hacker Over a year ago

I was talking about leftnav and rightnav, not direction. Now that you say that loadPage() doesn't seem to fire, it's totoally different issue, I guess your event listener doesn't fire at all then. Tried putting debug something in there?

cmplieger Over a year ago

the event does load when i remove the if else statements. And i see what you mean now, leftnav and rightnav are the variable values so i should add quotes around it i guess.

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