> For the complete documentation index, see [llms.txt](https://boxlang.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://boxlang.ortusbooks.com/boxlang-language/reference/built-in-functions/list/listremoveduplicates.md).

# ListRemoveDuplicates

De-duplicates a delimited list - either case-sensitively or case-insenstively

## Method Signature

```
ListRemoveDuplicates(list=[string], delimiter=[string], ignoreCase=[boolean], includeEmptyFields=[boolean], multiCharacterDelimiter=[boolean])
```

### Arguments

| Argument                  | Type      | Required | Description                                                                    | Default |
| ------------------------- | --------- | -------- | ------------------------------------------------------------------------------ | ------- |
| `list`                    | `string`  | `true`   | The list to deduplicate                                                        |         |
| `delimiter`               | `string`  | `false`  | The delimiter of the list                                                      | `,`     |
| `ignoreCase`              | `boolean` | `false`  | Whether case should be ignored or not during deduplication - defaults to false | `false` |
| `includeEmptyFields`      | `boolean` | `false`  |                                                                                | `false` |
| `multiCharacterDelimiter` | `boolean` | `false`  | boolean whether the delimiter is multi-character                               | `false` |

## Examples

### Basic usage (case-sensitive)

Basic usage. Optional arguments left as defaults.

[Run Example](https://try.boxlang.io/?code=eJzLySwuCUrNzS9LdSktyMlMTixJLdZQUMrPS9UpKc%2FXKckoSk3VScsvLdJJyyxL1QGJgxlgCSUFTWsuAESpF6U%3D)

```java
listRemoveDuplicates( "one,two,three,four,five,one,five,three" );

```

Result: one,two,three,four,five

### Optional arguments usage (ignore case = true)

Optional arguments being set. Ignore case set to true

[Run Example](https://try.boxlang.io/?code=eJzLySwuCUrNzS9LdSktyMlMTixJLdZQUMrPS9UpKc%2FXKckoSk3VScsvLdJJyyxL1fH3c9UJCffXCfEIcnVV0lFQ0gESJUWlqQqa1lwAH%2BQYvQ%3D%3D)

```java
listRemoveDuplicates( "one,two,three,four,five,ONE,TWO,THREE", ",", true );

```

Result: one,two,three,four,five

### Additional Examples

[Run Example](https://try.boxlang.io/?code=eJxtjjEKwzAMRfecQnhqwJADJO3UsVNvUGIRG5TI2HJ9%2FSgmdAjdpPefPqIscAczf8SuXDJax4s9tpmrXViH7BFjQxqZsaspCHKRWOQGpOf9hZnJp4c58DDAhhUoqFWDeHAlUtAqzJBw5S%2B6jtoDL1XejTx%2Fyv%2F2k%2B3vsj9X)

```java
lst = "cat,mouse,dog,cat,cow,goat,sheep,cat,dog";
writeoutput( lst );
writeoutput( "<hr>" );
// new list with duplicates removed
lst = ListRemoveDuplicates( lst );
writeoutput( lst );

```

## Related

* [GetToken](/boxlang-language/reference/built-in-functions/list/gettoken.md)
* [ListAppend](/boxlang-language/reference/built-in-functions/list/listappend.md)
* [ListAvg](/boxlang-language/reference/built-in-functions/list/listavg.md)
* [ListChangeDelims](/boxlang-language/reference/built-in-functions/list/listchangedelims.md)
* [ListCompact](/boxlang-language/reference/built-in-functions/list/listcompact.md)
* [ListContains](/boxlang-language/reference/built-in-functions/list/listcontains.md)
* [ListContainsNoCase](/boxlang-language/reference/built-in-functions/list/listcontainsnocase.md)
* [ListDeleteAt](/boxlang-language/reference/built-in-functions/list/listdeleteat.md)
* [ListEach](/boxlang-language/reference/built-in-functions/list/listeach.md)
* [ListEvery](/boxlang-language/reference/built-in-functions/list/listevery.md)
* [ListFilter](/boxlang-language/reference/built-in-functions/list/listfilter.md)
* [ListFind](/boxlang-language/reference/built-in-functions/list/listfind.md)
* [ListFindNoCase](/boxlang-language/reference/built-in-functions/list/listfindnocase.md)
* [ListFirst](/boxlang-language/reference/built-in-functions/list/listfirst.md)
* [ListGetAt](/boxlang-language/reference/built-in-functions/list/listgetat.md)
* [ListGetEndings](/boxlang-language/reference/built-in-functions/list/listgetendings.md)
* [ListIndexExists](/boxlang-language/reference/built-in-functions/list/listindexexists.md)
* [ListInsertAt](/boxlang-language/reference/built-in-functions/list/listinsertat.md)
* [ListItemTrim](/boxlang-language/reference/built-in-functions/list/listitemtrim.md)
* [ListLast](/boxlang-language/reference/built-in-functions/list/listlast.md)
* [ListLen](/boxlang-language/reference/built-in-functions/list/listlen.md)
* [ListMap](/boxlang-language/reference/built-in-functions/list/listmap.md)
* [ListNone](/boxlang-language/reference/built-in-functions/list/listnone.md)
* [ListPrepend](/boxlang-language/reference/built-in-functions/list/listprepend.md)
* [ListQualify](/boxlang-language/reference/built-in-functions/list/listqualify.md)
* [ListReduceRight](/boxlang-language/reference/built-in-functions/list/listreduceright.md)
* [ListRest](/boxlang-language/reference/built-in-functions/list/listrest.md)
* [ListSetAt](/boxlang-language/reference/built-in-functions/list/listsetat.md)
* [ListSome](/boxlang-language/reference/built-in-functions/list/listsome.md)
* [ListSort](/boxlang-language/reference/built-in-functions/list/listsort.md)
* [ListToArray](/boxlang-language/reference/built-in-functions/list/listtoarray.md)
* [ListTrim](/boxlang-language/reference/built-in-functions/list/listtrim.md)
* [ListValueCount](/boxlang-language/reference/built-in-functions/list/listvaluecount.md)
* [ListValueCountNoCase](/boxlang-language/reference/built-in-functions/list/listvaluecountnocase.md)


---

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