---
updatedAt: 2026-10-01T18:39:04.000Z
agentTools:
  projectIndex: https://developer.roku.com/dev/llms.txt
---

# ifArrayJoin

Interface providing Join to concatenate array elements into a single string

## Implemented by

| Name                   | Description                                                                                                                                |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
| [roArray](https://developer.roku.com/dev/docs/roarray) | Stores an indexed collection of BrightScript objects. Each entry of an array can be a different type, or they may all be of the same type. |

## Supported methods

### Join(separator as String) as String

##### Description

Creates a string by joining all array elements together separated by the specified separator. All elements must be of type String; otherwise, an empty string is returned

##### Parameters

| Name      | Type   | Description                                       |
| --------- | ------ | ------------------------------------------------- |
| separator | String | The string used to separate elements in an array. |

##### Return Value

A String containing the array elements.

##### Examples

```brightscript
    a = ["ant","bat","cat"]
    s = a.Join(",")
    print """" + s + """"
    ' "ant,bat,cat"

    a = "abc".Split("")
    s = a.Join("--")
    print """" + s + """"
    ' "a--b--c"
```