# define an Array as @type{Array\]

**URL:** https://forum.servoy.com/t/define-an-array-as-type-array/14509
**Category:** Classic Servoy
**Created:** [August 19, 2011, 7:44am UTC](https://forum.servoy.com/t/define-an-array-as-type-array/14509 "2011-08-19T07:44:44Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![Harjo](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.servoy.com/harjo/32/4873_2.png) [@Harjo](https://forum.servoy.com/u/Harjo)
#### Post date: [August 19, 2011, 7:44am UTC](https://forum.servoy.com/t/define-an-array-as-type-array/14509/1 "2011-08-19T07:44:44Z")

</div>

HI there, I have a dataset.

```auto
function addToArray(dataset) {
	var dataArray = dataset.getColumnAsArray(1)
	if (selections) {
		var a = selections.split(',')
		dataArray = dataArray.concat(a)
	}
}

```

but that gives me warning: The function concat() is undefined in this script  
So I have to do this:

```auto
function addToArray(dataset) {
	/**@type {Array} */
	var dataArray = dataset.getColumnAsArray(1)
	if (selections) {
		var a = selections.split(',')
		dataArray = dataArray.concat(a)
	}
}

```

Why do I have to add /\*\*@type {Array} \*/ ?  
Servoy does or can already know, that this is an Array??

---

<div class="post-metadata">

### Author: ![jcompagner](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.servoy.com/jcompagner/32/4889_2.png) [@jcompagner](https://forum.servoy.com/u/jcompagner)
#### Post date: [August 19, 2011, 1:50pm UTC](https://forum.servoy.com/t/define-an-array-as-type-array/14509/2 "2011-08-19T13:50:54Z")

</div>

this works fine for me:

```auto
/**
 * @param {JSDataSet} dataset
 *
 * @properties={typeid:24,uuid:"055E25C1-5B73-4451-8948-C598E7EC95E9"}
 */
function addToArray(dataset) {
   var dataArray = dataset.getColumnAsArray(1)
   if (selections) {
      var a = selections.split(',')
      dataArray = dataArray.concat(a)
   }
}

```

i don’t know if you did type dataset correctly as a param?