> 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/arrayflatmap.md). # ArrayFlatMap Maps each element and flattens the result one level. ``` values = [ 1, 2, 3 ]; values.flatMap( ( value ) => [ value, value * 10 ] ); // [ 1, 10, 2, 20, 3, 30 ] ``` ## Method Signature ``` ArrayFlatMap(array=[array], callback=[function:Function], parallel=[boolean], maxThreads=[any], virtual=[boolean]) ``` ### Arguments | Argument | Type | Required | Description | Default | | ------------ | ------------------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- | | `array` | `array` | `true` | The array to transform | | | `callback` | `function:Function` | `true` |

The function to invoke for each item. The function will be passed 3 arguments: the current item, and the
current index, and the original array. You can alternatively pass a Java Function which will only receive the 1st arg.

| | | `parallel` | `boolean` | `false` | If true, the function will be invoked in parallel using multiple threads. Defaults to false. | `false` | | `maxThreads` | `any` | `false` | The maximum number of threads to use when parallel is true. If not provided the common thread pool will be used. If a boolean value is passed, it will be assigned as the virtual argument. | | | `virtual` | `boolean` | `false` | If true, the function will be invoked using virtual thread. Defaults to false. Ignored if parallel is false. | `false` | ## Examples ## 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) * [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) * [ArrayReduce](/boxlang-language/reference/built-in-functions/array/arrayreduce.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) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://boxlang.ortusbooks.com/boxlang-language/reference/built-in-functions/array/arrayflatmap.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.