> 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/struct/structcopy.md).

# StructCopy

Creates a shallow copy of a struct.

Copies top-level keys, values, and arrays in the structure by value; copies nested structures by reference.

## Method Signature

```
StructCopy(struct=[structloose])
```

### Arguments

| Argument | Type     | Required | Description        | Default |
| -------- | -------- | -------- | ------------------ | ------- |
| `struct` | `struct` | `true`   | The struct to copy |         |

## Examples

### Copy a structure and change it. Original structure stays unchanged

[Run Example](https://try.boxlang.io/?code=eJzLrQwuKSpNLlGwVahW4OJUSlRSsFIw1AGykkAsIxArGcQy5qq15sqt9Esth2soBjOc8wsqNRRyYeZooqjScwKqM0URilZQSlFSiAWKm1hzQYxwSc1JLUkFGQJXpaMAshZoWHlRZkmqf2lJQWmJBtRG79RKn8ziEmRLFdQUlBQetU0CkmqYqhCO1gQZCQAMZEy5)

```java
myStruct = { 
	"a" : 1,
	"b" : 2,
	"c" : 3
};
myNewStruct = structCopy( myStruct );
myNewStruct.B = 5;
myNewStruct[ "d" ] = 4;
structDelete( myNewStruct, "c" );
writeOutput( structKeyList( myStruct ) & " → " & structKeyList( myNewStruct ) );

```

Result: b,a,c → b,a,d

### Additional Examples

[Run Example](https://try.boxlang.io/?code=eJxtkEFrgzAYhs%2FNr3jx1IK09w0P0tGx0wYd9JyaiMGYT2KsjLL%2FviRaUdaL8CXv9%2BTx5UY1XHfIcAfbHD8veEHSECUp23x9vIeJlKkT9vvKDgecKxpQ9NZK48DHXfbWN%2B0Wml%2BlzpLj%2BjJJceM2mybsIuVI7c8jgM7ZvnBwhJLbhoWPtznH0xDcYr0cFUIqhSaqO2hVy%2Bcup8DipZN2ydtNTvGlkZkL4QnkKp8cSXtclNbwZx5QSi8Y4ns2cvK2lUbMZinuvrv8O3YnafBtLWXnlPGDMoXuhexQcLe2zaffHJSrwi24EFI8LXDRgSDPCpoVv8n%2F0FhBQa2SAqWlZi7zKkuycQED71ZvPYr5A2vYsJc%3D)

```java
animals = { 
	COW : "moo",
	PIG : "oink"
};
// Show current animals
Dump( label="Current animals", var=animals );
// Copy animals struct to farm
farm = StructCopy( animals );
// Show farm, looks like animals
Dump( label="Farm after StructCopy()", var=farm );
// Add another animal. Will not affect farm.
StructAppend( animals, {
	CAT : "meow"
} );
// Show animals, now includes cat
Dump( label="Animals with cat added", var=animals );
// Show farm, does not have cat
Dump( label="Farm copied from animals before cat was added", var=farm );

```

## Related

* [StructAppend](/boxlang-language/reference/built-in-functions/struct/structappend.md)
* [StructClear](/boxlang-language/reference/built-in-functions/struct/structclear.md)
* [StructDelete](/boxlang-language/reference/built-in-functions/struct/structdelete.md)
* [StructEach](/boxlang-language/reference/built-in-functions/struct/structeach.md)
* [StructEquals](/boxlang-language/reference/built-in-functions/struct/structequals.md)
* [StructEvery](/boxlang-language/reference/built-in-functions/struct/structevery.md)
* [StructFilter](/boxlang-language/reference/built-in-functions/struct/structfilter.md)
* [StructFind](/boxlang-language/reference/built-in-functions/struct/structfind.md)
* [StructFindKey](/boxlang-language/reference/built-in-functions/struct/structfindkey.md)
* [StructFindValue](/boxlang-language/reference/built-in-functions/struct/structfindvalue.md)
* [StructGet](/boxlang-language/reference/built-in-functions/struct/structget.md)
* [StructGetMetadata](/boxlang-language/reference/built-in-functions/struct/structgetmetadata.md)
* [StructInsert](/boxlang-language/reference/built-in-functions/struct/structinsert.md)
* [StructIsCaseSensitive](/boxlang-language/reference/built-in-functions/struct/structiscasesensitive.md)
* [StructIsOrdered](/boxlang-language/reference/built-in-functions/struct/structisordered.md)
* [StructKeyArray](/boxlang-language/reference/built-in-functions/struct/structkeyarray.md)
* [StructKeyExists](/boxlang-language/reference/built-in-functions/struct/structkeyexists.md)
* [StructKeyList](/boxlang-language/reference/built-in-functions/struct/structkeylist.md)
* [StructKeyTranslate](/boxlang-language/reference/built-in-functions/struct/structkeytranslate.md)
* [StructMap](/boxlang-language/reference/built-in-functions/struct/structmap.md)
* [StructNew](/boxlang-language/reference/built-in-functions/struct/structnew.md)
* [StructNone](/boxlang-language/reference/built-in-functions/struct/structnone.md)
* [StructReduce](/boxlang-language/reference/built-in-functions/struct/structreduce.md)
* [StructSome](/boxlang-language/reference/built-in-functions/struct/structsome.md)
* [StructSort](/boxlang-language/reference/built-in-functions/struct/structsort.md)
* [StructToQueryString](/boxlang-language/reference/built-in-functions/struct/structtoquerystring.md)
* [StructToSorted](/boxlang-language/reference/built-in-functions/struct/structtosorted.md)
* [StructUpdate](/boxlang-language/reference/built-in-functions/struct/structupdate.md)
* [StructValueArray](/boxlang-language/reference/built-in-functions/struct/structvaluearray.md)


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