> 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/string/listreduce.md).

# ListReduce

Run the provided udf over a delimited list to reduce the values to a single output

## Method Signature

```
ListReduce(list=[string], callback=[function:BiFunction], initialValue=[any], delimiter=[string], includeEmptyFields=[boolean], multiCharacterDelimiter=[boolean])
```

### Arguments

| Argument                  | Type                  | Required | Description                                                                                                                                                                                             | Default |
| ------------------------- | --------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- |
| `list`                    | `string`              | `true`   | The delimited list to perform operations on                                                                                                                                                             |         |
| `callback`                | `function:BiFunction` | `true`   | The function to invoke for each item. The function will be passed 3 arguments: the value, the index, the array. You can alternatively pass a Java BiFunction which will only receive the ffirst 2 args. |         |
| `initialValue`            | `any`                 | `false`  | The initial value of the reduction                                                                                                                                                                      |         |
| `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                                                                                                                                                        | `true`  |

## Examples

### Script Syntax

[Run Example](https://try.boxlang.io/?code=eJxVjc8KgkAYxM%2F5FMN6MfoO2v8whZ4giOieudWCrrK7nxHRu7dml24z85thNNeFNBYZREJTmtGcFrSkFa1pQ0ks0sBy7WmlrDvIki8ygh42hAg7%2FURrZKcatqdzxZK%2BUddLjJHleAUjIx0b%2Fd%2FDZCilwZsQY5wGD6Oc3LNr2UUQx7tE%2F9xc4bws1U05i%2FB3HUJ543m4LUwu%2BvkHSig%2B6w%3D%3D)

```java
numbers = "1,2,3,4,5,6,7,8,9,10";
sum = listReduce( numbers, ( Any previousValue, Any value ) => {
	return previousValue + value;
}, 0 );
writeOutput( "The sum of the digits #numbers# is #sum#<br>" );

```

### Additional Examples

[Run Example](https://try.boxlang.io/?code=eJxVjsEKwjAQRM%2FmK4b00mIOioiH0oJfIIh4V7tqoE1LslsR8d9NW0G8zT4eO%2BOkOZMPKKCXZmXWZqNz5amSC1XHUx15bQPvR5DCTbZBiq17ovPU21ZCFIXMiPohIkNR4qVmnli8%2B%2Fcwn6RcvQ0WyHL18JZpJ9wJp9CHOyFIg%2FYKjrGyN8sBybc6gY3Hb2Cihw8fC7FAew%3D%3D)

```java
numbers = "1,3,5,7";
reducedVal = listReduce( numbers, ( Any previousValue, Any value ) => {
	return previousValue + value;
}, 0 );
writeOutput( "The sum of the digits #numbers# is #reducedVal#" );

```

## Related

* [Ascii](/boxlang-language/reference/built-in-functions/string/ascii.md)
* [CamelCase](/boxlang-language/reference/built-in-functions/string/camelcase.md)
* [Char](/boxlang-language/reference/built-in-functions/string/char.md)
* [CharsetDecode](/boxlang-language/reference/built-in-functions/string/charsetdecode.md)
* [CharsetEncode](/boxlang-language/reference/built-in-functions/string/charsetencode.md)
* [Compare](/boxlang-language/reference/built-in-functions/string/compare.md)
* [CompareNoCase](/boxlang-language/reference/built-in-functions/string/comparenocase.md)
* [Find](/boxlang-language/reference/built-in-functions/string/find.md)
* [FindNoCase](/boxlang-language/reference/built-in-functions/string/findnocase.md)
* [FindOneOf](/boxlang-language/reference/built-in-functions/string/findoneof.md)
* [Insert](/boxlang-language/reference/built-in-functions/string/insert.md)
* [JSStringFormat](/boxlang-language/reference/built-in-functions/string/jsstringformat.md)
* [Justify](/boxlang-language/reference/built-in-functions/string/justify.md)
* [KebabCase](/boxlang-language/reference/built-in-functions/string/kebabcase.md)
* [LCase](/boxlang-language/reference/built-in-functions/string/lcase.md)
* [Left](/boxlang-language/reference/built-in-functions/string/left.md)
* [LJustify](/boxlang-language/reference/built-in-functions/string/ljustify.md)
* [LTrim](/boxlang-language/reference/built-in-functions/string/ltrim.md)
* [Mid](/boxlang-language/reference/built-in-functions/string/mid.md)
* [ParagraphFormat](/boxlang-language/reference/built-in-functions/string/paragraphformat.md)
* [PascalCase](/boxlang-language/reference/built-in-functions/string/pascalcase.md)
* [QueryStringToStruct](/boxlang-language/reference/built-in-functions/string/querystringtostruct.md)
* [ReEscape](/boxlang-language/reference/built-in-functions/string/reescape.md)
* [ReFind](/boxlang-language/reference/built-in-functions/string/refind.md)
* [reFindNoCase](/boxlang-language/reference/built-in-functions/string/refindnocase.md)
* [ReMatch](/boxlang-language/reference/built-in-functions/string/rematch.md)
* [reMatchNoCase](/boxlang-language/reference/built-in-functions/string/rematchnocase.md)
* [RemoveChars](/boxlang-language/reference/built-in-functions/string/removechars.md)
* [RepeatString](/boxlang-language/reference/built-in-functions/string/repeatstring.md)
* [Replace](/boxlang-language/reference/built-in-functions/string/replace.md)
* [ReplaceList](/boxlang-language/reference/built-in-functions/string/replacelist.md)
* [ReplaceListNoCase](/boxlang-language/reference/built-in-functions/string/replacelistnocase.md)
* [ReplaceNoCase](/boxlang-language/reference/built-in-functions/string/replacenocase.md)
* [ReReplace](/boxlang-language/reference/built-in-functions/string/rereplace.md)
* [reReplaceNoCase](/boxlang-language/reference/built-in-functions/string/rereplacenocase.md)
* [Reverse](/boxlang-language/reference/built-in-functions/string/reverse.md)
* [Right](/boxlang-language/reference/built-in-functions/string/right.md)
* [RJustify](/boxlang-language/reference/built-in-functions/string/rjustify.md)
* [RTrim](/boxlang-language/reference/built-in-functions/string/rtrim.md)
* [Slugify](/boxlang-language/reference/built-in-functions/string/slugify.md)
* [SnakeCase](/boxlang-language/reference/built-in-functions/string/snakecase.md)
* [SpanExcluding](/boxlang-language/reference/built-in-functions/string/spanexcluding.md)
* [SpanIncluding](/boxlang-language/reference/built-in-functions/string/spanincluding.md)
* [SQLPrettify](/boxlang-language/reference/built-in-functions/string/sqlprettify.md)
* [StringBind](/boxlang-language/reference/built-in-functions/string/stringbind.md)
* [StringEach](/boxlang-language/reference/built-in-functions/string/stringeach.md)
* [StringEvery](/boxlang-language/reference/built-in-functions/string/stringevery.md)
* [StringFilter](/boxlang-language/reference/built-in-functions/string/stringfilter.md)
* [StringMap](/boxlang-language/reference/built-in-functions/string/stringmap.md)
* [StringReduce](/boxlang-language/reference/built-in-functions/string/stringreduce.md)
* [StringReduceRight](/boxlang-language/reference/built-in-functions/string/stringreduceright.md)
* [StringSome](/boxlang-language/reference/built-in-functions/string/stringsome.md)
* [StringSort](/boxlang-language/reference/built-in-functions/string/stringsort.md)
* [StripCR](/boxlang-language/reference/built-in-functions/string/stripcr.md)
* [Trim](/boxlang-language/reference/built-in-functions/string/trim.md)
* [TrueFalseFormat](/boxlang-language/reference/built-in-functions/string/truefalseformat.md)
* [UCase](/boxlang-language/reference/built-in-functions/string/ucase.md)
* [UCFirst](/boxlang-language/reference/built-in-functions/string/ucfirst.md)
* [Val](/boxlang-language/reference/built-in-functions/string/val.md)
* [Wrap](/boxlang-language/reference/built-in-functions/string/wrap.md)
* [YesNoFormat](/boxlang-language/reference/built-in-functions/string/yesnoformat.md)


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