> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/developers/paramml-developer-guide/functions/custom-function/concat-list1-list2.md).

# concat (List1, List2)

The function takes two separate lists as input and combines them into a single list. The result is a merged version of the two input lists, with all the elements from both lists present in the output list in the order they were provided.

The resulting list is showing in the list3 parameter.

**Example:**

**concat (List1, List2) → List of list**

```xml
<O N="concatObject1" T="Project" Category="Functions" TransAlignRule="1">
    <!-- created by ParamML Examples on 13.02.2023 -->
    <O N="F1" T="Group">
        <P N="List1" V="[10,5,20]" />
        <P N="List2" V="[12,16,18]" />
        <P N="List3" V="concat(List1,List2)" />
    </O>
    <O N="F2" T="Group">
        <P N="List1" V="[[10,5],[20,15]]" />
        <P N="List2" V="[[12,14],[16,18]]" />
        <P N="List3" V="concat(List1,List2)" />
    </O>
</O>
```

![](https://openbrim.atlassian.net/wiki/download/attachments/2167898133/image-20230213-140920.png?api=v2) To view this example in the library, see (<https://openbrim.org/platform/?application=inc&author=ParamML_Examples_OpenBrIM+Platform&folder=Functions&obj=objidsok237q52xn1m9ds05z1fj>)

**Example:**

```xml
<O N="concatObject2" T="Project" Category="Functions" TransAlignRule="1">
    <!-- created by ParamML Examples on 13.02.2023 -->
    <P N="List1" V="[0,1,2,3,4,5,6,7,8,9]" />
    <P N="Line1" V="[[10,15,20],[15,20,25],1]" />
    <P N="concatexample" V="concat(List1, Line1)" />
</O>
```

![](https://openbrim.atlassian.net/wiki/download/attachments/2167898133/image-20230213-141713.png?api=v2) To view this example in the library, see (<https://openbrim.org/platform/?application=inc&author=ParamML_Examples_OpenBrIM+Platform&folder=Functions&obj=objidfsras7eoxccgy2td9iq8hk>)


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