> 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/array/arrayreduce.md).

# ArrayReduce

Run the provided udf over the array to reduce the values to a single output

## Method Signature

```
ArrayReduce(array=[array], callback=[function:BiFunction], initialValue=[any])
```

### Arguments

| Argument       | Type                  | Required | Description                                                                                                                                                                                                                                                                                     | Default |
| -------------- | --------------------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- |
| `array`        | `array`               | `true`   | The array to reduce                                                                                                                                                                                                                                                                             |         |
| `callback`     | `function:BiFunction` | `true`   | <p>The function to invoke for each item. The function will be passed 3 arguments: the accumulator, the current item, and the<br>current index. You can alternatively pass a Java BiFunction which will only receive the first 2 args. The function should return the new accumulator value.</p> |         |
| `initialValue` | `any`                 | `false`  | The initial value of the accumulator                                                                                                                                                                                                                                                            |         |

## Examples

### Simple arrayReduce Example

Sum each `a` element in the array

[Run Example](https://try.boxlang.io/?code=eJxVjcEKwjAQRM%2FZr5hjikEsKIilQsC74FU8hLgHoUlDTNQi%2FXdjQYq3fTuzb23vQsevg0kGLc4g8SYhNHZYkxjVjPX2nzd1Ybo0dM%2BuXJoYzXDia7YsYWepgoT2A0Lkh5om7tixT6jQ7lFskVOOfipg8UuXuqFRYYWqoWe8JT7mFHKS%2BH4ruw8PZTLx)

```java
complexData = [ 
	{
		A : 4
	},
	{
		A : 18
	},
	{
		A : 51
	}
];
sum = arrayReduce( complexData, ( Any prev, Any element ) => {
	return prev + element.A;
}, 0 );
writeOutput( sum );

```

Result: 73

### Additional Examples

[Run Example](https://try.boxlang.io?code=eJyVjs0KglAQhdfOUxzuwh8S1GonBr5C22hx0yGDm8akkUTv3uXqwkUtYjhwhrP4PuF6qLhGgVJEj3v3hjiAvCwmb22zsdnSMUaIsh1RaZExdvWhzcCIUOzwIk%2B4H6SddqymMad3jBRRTvVwvYWQGRflSBKMFzb1HVlK8kODPNWwMZ2yDqpvWNi1U%2Fc0uj2rf618KHv%2Bwk2pb3K0sAucABwcMzigD5k6WtY%3D)

```java
reduced = ArrayReduce( [ 
	1,
	2,
	3,
	4
], ( Any carry, Any value ) => {
	return carry + value;
}, 0 );
dump( reduced ); // yields 10
reduced = ArrayReduce( [
	"hello",
	"there",
	"boxlang"
], ( Any carry, Any value ) => {
	return carry & " " & value;
}, "" );
dump( reduced );
 // yields 'hello there boxlang'

```

## Related

* [ArrayAppend](/boxlang-language/reference/built-in-functions/array/arrayappend.md)
* [ArrayAvg](/boxlang-language/reference/built-in-functions/array/arrayavg.md)
* [ArrayChunk](/boxlang-language/reference/built-in-functions/array/arraychunk.md)
* [ArrayClear](/boxlang-language/reference/built-in-functions/array/arrayclear.md)
* [ArrayContains](/boxlang-language/reference/built-in-functions/array/arraycontains.md)
* [ArrayContainsNoCase](/boxlang-language/reference/built-in-functions/array/arraycontainsnocase.md)
* [ArrayDelete](/boxlang-language/reference/built-in-functions/array/arraydelete.md)
* [ArrayDeleteAt](/boxlang-language/reference/built-in-functions/array/arraydeleteat.md)
* [ArrayDeleteNoCase](/boxlang-language/reference/built-in-functions/array/arraydeletenocase.md)
* [ArrayEach](/boxlang-language/reference/built-in-functions/array/arrayeach.md)
* [ArrayEvery](/boxlang-language/reference/built-in-functions/array/arrayevery.md)
* [ArrayFilter](/boxlang-language/reference/built-in-functions/array/arrayfilter.md)
* [ArrayFind](/boxlang-language/reference/built-in-functions/array/arrayfind.md)
* [ArrayFindAll](/boxlang-language/reference/built-in-functions/array/arrayfindall.md)
* [ArrayFindAllNoCase](/boxlang-language/reference/built-in-functions/array/arrayfindallnocase.md)
* [ArrayFindFirst](/boxlang-language/reference/built-in-functions/array/arrayfindfirst.md)
* [ArrayFindNoCase](/boxlang-language/reference/built-in-functions/array/arrayfindnocase.md)
* [ArrayFirst](/boxlang-language/reference/built-in-functions/array/arrayfirst.md)
* [ArrayFlatMap](/boxlang-language/reference/built-in-functions/array/arrayflatmap.md)
* [ArrayFlatten](/boxlang-language/reference/built-in-functions/array/arrayflatten.md)
* [ArrayGetMetadata](/boxlang-language/reference/built-in-functions/array/arraygetmetadata.md)
* [ArrayGroupBy](/boxlang-language/reference/built-in-functions/array/arraygroupby.md)
* [ArrayIndexExists](/boxlang-language/reference/built-in-functions/array/arrayindexexists.md)
* [ArrayInsertAt](/boxlang-language/reference/built-in-functions/array/arrayinsertat.md)
* [ArrayIsDefined](/boxlang-language/reference/built-in-functions/array/arrayisdefined.md)
* [ArrayLast](/boxlang-language/reference/built-in-functions/array/arraylast.md)
* [ArrayMap](/boxlang-language/reference/built-in-functions/array/arraymap.md)
* [ArrayMax](/boxlang-language/reference/built-in-functions/array/arraymax.md)
* [ArrayMedian](/boxlang-language/reference/built-in-functions/array/arraymedian.md)
* [ArrayMerge](/boxlang-language/reference/built-in-functions/array/arraymerge.md)
* [ArrayMid](/boxlang-language/reference/built-in-functions/array/arraymid.md)
* [ArrayMin](/boxlang-language/reference/built-in-functions/array/arraymin.md)
* [ArrayNew](/boxlang-language/reference/built-in-functions/array/arraynew.md)
* [ArrayNone](/boxlang-language/reference/built-in-functions/array/arraynone.md)
* [ArrayPop](/boxlang-language/reference/built-in-functions/array/arraypop.md)
* [ArrayPrepend](/boxlang-language/reference/built-in-functions/array/arrayprepend.md)
* [ArrayPush](/boxlang-language/reference/built-in-functions/array/arraypush.md)
* [ArrayRange](/boxlang-language/reference/built-in-functions/array/arrayrange.md)
* [ArrayReduceRight](/boxlang-language/reference/built-in-functions/array/arrayreduceright.md)
* [ArrayReject](/boxlang-language/reference/built-in-functions/array/arrayreject.md)
* [ArrayResize](/boxlang-language/reference/built-in-functions/array/arrayresize.md)
* [ArrayReverse](/boxlang-language/reference/built-in-functions/array/arrayreverse.md)
* [ArraySet](/boxlang-language/reference/built-in-functions/array/arrayset.md)
* [ArrayShift](/boxlang-language/reference/built-in-functions/array/arrayshift.md)
* [ArraySlice](/boxlang-language/reference/built-in-functions/array/arrayslice.md)
* [ArraySome](/boxlang-language/reference/built-in-functions/array/arraysome.md)
* [ArraySort](/boxlang-language/reference/built-in-functions/array/arraysort.md)
* [ArraySplice](/boxlang-language/reference/built-in-functions/array/arraysplice.md)
* [ArraySum](/boxlang-language/reference/built-in-functions/array/arraysum.md)
* [ArraySwap](/boxlang-language/reference/built-in-functions/array/arrayswap.md)
* [ArrayToList](/boxlang-language/reference/built-in-functions/array/arraytolist.md)
* [ArrayToStruct](/boxlang-language/reference/built-in-functions/array/arraytostruct.md)
* [ArrayTranspose](/boxlang-language/reference/built-in-functions/array/arraytranspose.md)
* [ArrayUnique](/boxlang-language/reference/built-in-functions/array/arrayunique.md)
* [ArrayUnshift](/boxlang-language/reference/built-in-functions/array/arrayunshift.md)
* [ArrayZip](/boxlang-language/reference/built-in-functions/array/arrayzip.md)


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