# Join array

> Supported in: Batch, Faster, Streaming

Joins array with specified separator.

**Expression categories:** Array

## Declared arguments

* **Array to join:** Array to join on.<br>*Expression\<Array\<String>>*
* **Separator:** Separator to join array with.<br>*Expression\<String>*

**Output type:** *String*

## Examples

### Example 1: Base case

**Argument values:**

* **Array to join:** \[ hello, world ]
* **Separator:** -

**Output:** hello-world

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### Example 2: Base case

**Argument values:**

* **Array to join:** \[ hello, world ]
* **Separator:** <br>

**Output:** hello<br>world

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### Example 3: Null case (ANSI mode on)

**Argument values:**

* **Array to join:** `array`
* **Separator:** `separator`

| array | separator | **Output** |
| ----- | ----- | ----- |
| \[ hello, world ] | - | hello-world |
| \[ hello, world ] | *empty string* | helloworld |
| \[ hello, world ] | *null* | *null* |
| *null* | - | *null* |
| *null* | *null* | *null* |

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### Example 4: Null case (ANSI mode off)

**Argument values:**

* **Array to join:** `array`
* **Separator:** `separator`

| array | separator | **Output** |
| ----- | ----- | ----- |
| \[ hello, world ] | - | hello-world |
| \[ hello, world ] | *null* | helloworld |
| *null* | - | *null* |
| *null* | *null* | *null* |

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### Example 5: Edge case

**Argument values:**

* **Array to join:** \[  ]
* **Separator:** -

**Output:** *empty string*

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