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