# Array concat

> Supported in: Batch, Faster, Streaming

Concatenates the provided arrays into a single array, without de-duplication.

**Expression categories:** Array

## Declared arguments

* **Expressions:** A list of arrays to concatenate.<br>*List\<Expression\<Array\<T>>>*

**Type variable bounds:** *T accepts AnyType*

**Output type:** *Array\<T>*

## Examples

### Example 1: Base case

**Argument values:**

* **Expressions:** \[\[ 1, 2, 3 ], \[ 4, 5 ]]

**Output:** \[ 1, 2, 3, 4, 5 ]

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### Example 2: Base case

**Argument values:**

* **Expressions:** \[\[ 1, 2, 3 ], \[ 3, 4 ], \[ 4, 5 ]]

**Output:** \[ 1, 2, 3, 3, 4, 4, 5 ]

***

### Example 3: Base case

**Argument values:**

* **Expressions:** \[\[ 1, 2, 3 ], \[ 3, 4 ]]

**Output:** \[ 1, 2, 3, 3, 4 ]

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

**Argument values:**

* **Expressions:** \[`first_array`, `second_array`]

| first\_array | second\_array | **Output** |
| ----- | ----- | ----- |
| \[ 1, 2 ] | \[ 3, 4 ] | \[ 1, 2, 3, 4 ] |
| \[ 1, 2, 3 ] | *null* | *null* |
| *null* | *null* | *null* |

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### Example 5: Null case (ANSI mode off)

**Argument values:**

* **Expressions:** \[`first_array`, `second_array`]

| first\_array | second\_array | **Output** |
| ----- | ----- | ----- |
| \[ 1, 2 ] | \[ 3, 4 ] | \[ 1, 2, 3, 4 ] |
| \[ 1, 2, 3 ] | *null* | \[ 1, 2, 3 ] |
| *null* | *null* | \[  ] |

***