javascript: calling function in for-loop

Question

loop that executes a function. However, the following works - the counter counts while the images on the page are loaded.

var progress = function()
 {
   for (var i = 0; i < slide.length; i++)
    slide[i].onload = function(){
         actualprogress +=1,
         loading.innerHTML = actualprogress
    };
 }

While the following does not work. When I open the Page the counter says "[n]" (number of slides, e.g. "12") from the beginning.

var progress = function()
 {
   var action = function(){
     actualprogress +=1;
     loading.innerHTML = actualprogress
   }
   for (var i = 0; i < slide.length; i++)
     slide[i].onload = action();
 }

I would like to call a function from the for-loop because I will need to do other and more things within the function. Why doesn't this work?

Also think about using indentation

PeeHaa
– PeeHaa

2012-11-10 18:05:20 +00:00
Commented Nov 10, 2012 at 18:05 — PeeHaa
– PeeHaa, Commented Nov 10, 2012 at 18:05
I did now, sorry about that and thank you for telling me!

basbebe
– basbebe

2012-11-10 18:15:55 +00:00
Commented Nov 10, 2012 at 18:15 — basbebe
– basbebe, Commented Nov 10, 2012 at 18:15

Rikki · Accepted Answer · 2012-11-10 18:24:53Z

2

In the first code you are assigning the function pointer to the onload property.

In the second code you are assigning the function returned value to the onload property which is null.

There is a huge difference between those. The parantheses are extra in the second code, after action.

onload = action() => onload = action

Cheers

edited Nov 10, 2012 at 18:24

answered Nov 10, 2012 at 18:06

Rikki

3,5681 gold badge25 silver badges34 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Renato Zannon · Accepted Answer · 2012-11-10 18:07:17Z

2

On the last line of the second snippet, you're calling the function, instead of just assigning it to slide[i].onload.

Simply change slide[i].onload = action(); to slide[i].onload = action;.

answered Nov 10, 2012 at 18:07

Renato Zannon

30.2k7 gold badges42 silver badges47 bronze badges

Collectives™ on Stack Overflow

javascript: calling function in for-loop

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related