# ListAppend

Appends an element to a list

## Method Signature

```
ListAppend(list=[string], value=[string], delimiter=[string], includeEmptyFields=[boolean], multiCharacterDelimiter=[boolean])
```

### Arguments

| Argument                  | Type      | Required | Description                                                    | Default |
| ------------------------- | --------- | -------- | -------------------------------------------------------------- | ------- |
| `list`                    | `string`  | `true`   | string list to filter entries from                             |         |
| `value`                   | `string`  | `true`   | The value to append                                            |         |
| `delimiter`               | `string`  | `false`  | string the list delimiter                                      | `,`     |
| `includeEmptyFields`      | `boolean` | `false`  | boolean whether to include empty fields in the returned result | `false` |
| `multiCharacterDelimiter` | `boolean` | `false`  | boolean whether the delimiter is multi-character               | `false` |

## Examples

### Simple listAppend Example

Add 'foo' to the end of this list

[Run Example](https://try.boxlang.io/?code=eJzLz0nxySwuUbBVUEpKLNIBYiMla6681HKoaA6QciwoSM1L0VDIh6jVUVBKy89XUtC05iovyixJ9S8tKSgtgUsrqCko6eraKQFpmDFAlQDxyCCh)

```java
oldList = "bar,bar2";
newList = listAppend( oldList, "foo" );
writeOutput( oldList & "-->" & newList );

```

Result: bar,bar2,foo

### Simple listAppend Example with Delimiter

Add 'foo' to the end of this list using a custom delimiter

[Run Example](https://try.boxlang.io/?code=eJzLz0nxySwuUbBVUEpKLNIBYiMla6681HKoaA6QciwoSM1L0VDIh6jVUVBKy89XAlI1Sgqa1lzlRZklqf6lJQWlJXA1CmoKSrq6dkpAGmYWUCUAhFMhrQ%3D%3D)

```java
oldList = "bar,bar2";
newList = listAppend( oldList, "foo", "|" );
writeOutput( oldList & "-->" & newList );

```

Result: bar,bar2|foo

### Simple listAppend Example with Empty Fields On

CF2018+ Add 'foo,,' to the end of this list using includeEmptyFields as true

[Run Example](https://try.boxlang.io/?code=eJzLz0nxySwuUbBVUEpKLNIBYiMla6681HKoaA6QciwoSM1L0VDIh6jVUVBKy8%2FX0VECMkBESVFpqoKmNVd5UWZJqn9pSUFpCVytgpqCkq6unRKQhpkJVAkAiv8jwQ%3D%3D)

```java
oldList = "bar,bar2";
newList = listAppend( oldList, "foo,,", ",", true );
writeOutput( oldList & "-->" & newList );

```

Result: bar,bar2,foo,,

### Simple listAppend Example with Empty Fields Off

CF2018+ Add 'foo' to the end of this list using includeEmptyFields as false

[Run Example](https://try.boxlang.io/?code=eJzLz0nxySwuUbBVUEpKLNIBYiMla6681HKoaA6QciwoSM1L0VDIh6jVUVBKy8%2FX0VECMkBEWmJOcaqCpjVXeVFmSap%2FaUlBaQlcsYKagpKurp0SkIYZClQJAK6NJAw%3D)

```java
oldList = "bar,bar2";
newList = listAppend( oldList, "foo,,", ",", false );
writeOutput( oldList & "-->" & newList );

```

Result: bar,bar2,foo

### Additional Examples

[Run Example](https://try.boxlang.io/?code=eJxVjr0KAjEQhPs8xZBGheD1HhaCjc29QzCrFzA%2FJBvivb254IFWC%2FPN7IxbXjYzzpDBk%2BIaFM%2BJSI7CLZ7qF67nEiN5s4frCQX5CCVJHEYxDJgCE3jW%2FGPFPZFmytBonzo44sYwgbLfMUo0uqcI9G7Q%2Bmc3nURNlulaXNza1pY%2FcZvW9A%2BFhkMn)

```java
mylist = "one,two,three";
mynewlist = listAppend( mylist, "four" );
// Note that listAppend creates a new list. It doesn't update the existing list:
writeDump( mylist );
writeDump( mynewlist );

```

[Run Example](https://try.boxlang.io/?code=eJzLrczJLC5RsFVQSsvPV7Lmyq3MSy2HCoEox4KC1LwUDYVcsDodBaWkxCIlIFWjpKBpzVVelFmS6lKaWwBSANMIFAcA50scNg%3D%3D)

```java
mylist = "foo";
mynewlist = listAppend( mylist, "bar", "|" );
writeDump( mynewlist );

```

## Related

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


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