# Invalid slide length when using $ionicSlideBoxDelegate, how to?

**URL:** <https://forum.ionicframework.com/t/invalid-slide-length-when-using-ionicslideboxdelegate-how-to/30961>\
**Category:** uncategorized\
**Created:** [August 22, 2015, 6:33am UTC](https://forum.ionicframework.com/t/invalid-slide-length-when-using-ionicslideboxdelegate-how-to/30961 "2015-08-22T06:33:22Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![patrioticcow](https://sea1.discourse-cdn.com/ionicframework/user_avatar/forum.ionicframework.com/patrioticcow/32/7616_2.png) [@patrioticcow](https://forum.ionicframework.com/u/patrioticcow)\
**Post date:** [August 22, 2015, 6:33am UTC](https://forum.ionicframework.com/t/invalid-slide-length-when-using-ionicslideboxdelegate-how-to/30961/1 "2015-08-22T06:33:22Z")

</div>

in `v1.1.0`, in `ionic.bundle.js`, when using `$ionicSlideBoxDelegate.next();` i get

`Cannot read property 'length' of undefined`

it’s in this function, the `slides.length`, `slides is undefined`:

```
function next(slideSpeed) {
  if (options.continuous) slide(index + 1, slideSpeed);
  else if (index < slides.length - 1) slide(index + 1, slideSpeed);
}

```

It was working fine with `v.1.0.` .Im not doing anything special just getting some data from `firebase` and building an array to do a `ng-repeat` on.

if i change it to `slides !== undefined && index < slides.length - 1` it works fine.

---

<div class="post-metadata">

**Author:** ![lucbonnin](https://sea1.discourse-cdn.com/ionicframework/user_avatar/forum.ionicframework.com/lucbonnin/32/94806_2.png) [@lucbonnin](https://forum.ionicframework.com/u/lucbonnin)\
**Post date:** [December 17, 2015, 1:49pm UTC](https://forum.ionicframework.com/t/invalid-slide-length-when-using-ionicslideboxdelegate-how-to/30961/2 "2015-12-17T13:49:05Z")

</div>

same issue with v1.1.1