# Function

Function task executes JavaScript or Groovy script.

![](https://support.xnarum.com/download/manuals/ISM-Manual-2023.fld/image326.png)

## **Input**

 

<table><thead><tr><th width="204">Attribute</th><th>Description</th></tr></thead><tbody><tr><td>Script Type</td><td>JavaScript or Groovy</td></tr><tr><td>Function</td><td>Script contents</td></tr></tbody></table>

&#x20;

## **Output**

&#x20;

<table><thead><tr><th width="207">Attribute</th><th>Description</th></tr></thead><tbody><tr><td>ResultValue</td><td>The return value from the script, if exists.</td></tr><tr><td>UseDataStructure</td><td>Map data structure to the return value. This is used at mapping component.</td></tr><tr><td>DataStructureId</td><td>Data structure id for future mapping.</td></tr></tbody></table>

&#x20;

## **Example**

&#x20;

### **JavaScript**

JDK provides JavaScript engine named Nashorn and this engine is removed since JDK 15. After JDK 15, gravalVM is used as an alternative of Nashorn engine.

And there is a slight change on JavaScript function execution after JDK 8.

<table><thead><tr><th width="158">Sccript</th><th>Result</th></tr></thead><tbody><tr><td>8</td><td><p>Named function can be executed.</p><p>The last function is executed if unnamed function does not exist.</p><p>Unnamed function has the highest priority.</p></td></tr><tr><td>9+</td><td><p>Named function cannot be executed.</p><p>Unnamed function is executed.</p></td></tr></tbody></table>

&#x20;

#### JDK 8

<table><thead><tr><th width="368">Sccript</th><th>Result</th></tr></thead><tbody><tr><td><p>function hello () {</p><p>    return "Hello";</p><p>}</p></td><td>Hello</td></tr><tr><td><p>function () {</p><p>    return "Hello";</p><p>}</p></td><td>Hello</td></tr><tr><td><p>function add(a,b) {</p><p>    return a + b;</p><p>}</p><p>function a () {</p><p>    return add(1,2);</p><p>}</p></td><td>3.0</td></tr><tr><td><p>function a(a, b) {</p><p>return a + b;</p><p>}</p><p> </p><p>function () {</p><p>  return a(1,2);</p><p>}</p><p> </p><p>function b() {</p><p>return "Hello";</p><p>}</p></td><td>3.0</td></tr></tbody></table>

#### JDK 9+

<table><thead><tr><th width="370">Sccript</th><th>Result</th></tr></thead><tbody><tr><td><p>function hello () {</p><p>    return "Hello";</p><p>}</p></td><td>Error</td></tr><tr><td><p>function () {</p><p>    return "Hello";</p><p>}</p></td><td>Hello</td></tr><tr><td><p>function add(a,b) {</p><p>    return a + b;</p><p>}</p><p>function () {</p><p>    return add(1,2);</p><p>}</p></td><td>3</td></tr></tbody></table>

&#x20;

### **Groovy**

This is the definition of Groovy (from Wikipedia)

| Apache Groovy is a [Java](https://en.wikipedia.org/wiki/Java_\(programming_language\))-syntax-compatible [object-oriented](https://en.wikipedia.org/wiki/Object-oriented_programming) [programming language](https://en.wikipedia.org/wiki/Programming_language) for the [Java platform](https://en.wikipedia.org/wiki/Java_\(software_platform\)). It is both a static and [dynamic](https://en.wikipedia.org/wiki/Dynamic_programming_language) language with features similar to those of [Python](https://en.wikipedia.org/wiki/Python_\(programming_language\)), [Ruby](https://en.wikipedia.org/wiki/Ruby_\(programming_language\)), and [Smalltalk](https://en.wikipedia.org/wiki/Smalltalk). It can be used as both a [programming language](https://en.wikipedia.org/wiki/Programming_language) and a [scripting language](https://en.wikipedia.org/wiki/Scripting_language) for the Java Platform, is compiled to [Java virtual machine](https://en.wikipedia.org/wiki/Java_virtual_machine) (JVM) [bytecode](https://en.wikipedia.org/wiki/Bytecode), and interoperates seamlessly with other Java code and [libraries](https://en.wikipedia.org/wiki/Library_\(computing\)). |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

The example script of Groovy is like this.

```
def func() {
    return "Hello";
}
return func();
```