[g37752]

checkboxes take 1 minute to show as checked.

the problem went away after a few days. i did not really find the problem/solution. Now it comes back?

what can be the problem?

[raghav.naganathan]

Can you please post the code that you are having problem with? It will be helpful to find out which part of your program is causing the error.

regards,
Raghav

[g37752]

here is the page that is slow on IE, but not on firefox.

the page is relatively fast now (still takes 5 sec to show), but it can be very slow

This post has been edited by g37752: 10 January 2013 - 10:55 PM

[raghav.naganathan]

Well, you can always use setTimeOut function to reduce the delays.

regards,
Raghav

This post has been edited by raghav.naganathan: 10 January 2013 - 09:59 PM

[g37752]

the problem is it goes through 2700 checkbox to see if any of them is checked.

how do i speed it up?
and why firefox does not have the problem?

[g37752]

any part of the following can be made more efficient?

for(var i=0;i<c.length;i++){
   if(c[i].checked)
   {
       ....
   }
   str=selected.toString();
   document.getElementById("selected").innerHTML=str;	 
}

the loop length is 2700.

[raghav.naganathan]

I did a small search and I came across this link.

Do take a look and see if it helps you.

regards,
Raghav

[g37752]

thanks, i did improve by moving stuff out of the loop.

[raghav.naganathan]

Glad it helped you...

regards,
Raghav

[Dormilich]

g37752, on 11 January 2013 - 07:10 AM, said:

any part of the following can be made more efficient?

for(var i=0;i<c.length;i++){
   // ...	 
}

the loop length is 2700.

1) never calculate the end condition (c.length) of a loop, if it doesn’t change (and the length keeps constant here).
for (var i = 0, l = c.length; i < l; i++)
for (var l = c.length; l--;​)

2) omitting whitespace does not make your code run faster, only less readable.

This post has been edited by Dormilich: 11 January 2013 - 01:39 AM

[andrewsw]

g37752, on 10 January 2013 - 11:10 PM, said:

any part of the following can be made more efficient?

for(var i=0;i<c.length;i++){
   if(c[i].checked)
   {
       ....
   }
   str=selected.toString();
   document.getElementById("selected").innerHTML=str;	 
}

the loop length is 2700.

You haven't shown much code, but the last two lines could be

document.getElementById("selected").innerHTML = str selected + '';

but you should also do this before the loop:

var selec = document.getElementById("selected");
// then
selec.innerHTML = selected + '';

If, as it seems, you are setting the innerHTML repeatedly (within the loop) then only the last assignment will remain?! If you are only looking for the last selected (checked?) item then you should start at the end and work backwards, using break to break out of the loop.

I think you should show more of your code.

This post has been edited by andrewsw: 11 January 2013 - 03:40 AM

[Dormilich]

andrewsw, on 11 January 2013 - 11:20 AM, said:

You haven't shown much code, but the last two lines could be

document.getElementById("selected").innerHTML = str + '';

what good does adding an empty string would have here? str is already a string.

[andrewsw]

Dormilich, on 11 January 2013 - 03:23 AM, said:

andrewsw, on 11 January 2013 - 11:20 AM, said:

You haven't shown much code, but the last two lines could be

document.getElementById("selected").innerHTML = str + '';

what good does adding an empty string would have here? str is already a string.

I don't think it is necessary at all (especially if str is already a string) but I'm encouraging the OP not to use the (slow) function call toString(). Even if selected were a number it wouldn't be necessary. Oops, I meant:

document.getElementById("selected").innerHTML = selected + '';

This post has been edited by andrewsw: 11 January 2013 - 03:32 AM

[Dormilich]

I need to raise a point here. no matter which way of converting to string you use, if the variable doesn’t hold a string the .toString() method will always be used, whether directly or indirectly.

[andrewsw]

@Dormilich
You're right! I had believed, for some reason, that a specific call to toString() is slower than + ''.

It even seems that (1234) + '' may even be slower than (1234).toString(), which seems strange.