---
name: "SoSelectOne"
section: "3iv"
platform: "linux"
package: "inventor-doc"
version: "2.1.6+ds-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/SoSelectOne/3iv"
---

# SoSelectOne(3iv)

selects one value from a multiple-value field.

## NAME

SoSelectOne — selects one value from a multiple-value field.

## INHERITS FROM

SoBase \> SoFieldContainer \> SoEngine \> SoSelectOne

## SYNOPSIS

**#include \<Inventor/engines/SoSelectOne.h\>**

Inputs from class SoSelectOne:

**SoSFInt32**	**index**\
 **\<inputType\>**	**input**

Outputs from class SoSelectOne:

**(\<outputType\>)**	**output**

Methods from class SoSelectOne:

	**SoSelectOne(SoType inputType)**

Methods from class SoEngine:

**static SoType**	**getClassTypeId()**\
 **virtual int**	**getOutputs(SoEngineOutputList &list) const**\
 **SoEngineOutput \***	**getOutput(const SbName &outputName) const**\
 **SbBool**	**getOutputName(const SoEngineOutput \*output, SbName &outputName) const**\
 **SoEngine \***	**copy() const**\
 **static SoEngine \***	**getByName(const SbName &name)**\
 **static int**	**getByName(const SbName &name, SoEngineList &list)**

Methods from class SoFieldContainer:

**void**	**setToDefaults()**\
 **SbBool**	**hasDefaultValues() const**\
 **SbBool**	**fieldsAreEqual(const SoFieldContainer \*fc) const**\
 **void**	**copyFieldValues(const SoFieldContainer \*fc, SbBool copyConnections = FALSE)**\
 **SbBool**	**set(const char \*fieldDataString)**\
 **void**	**get(SbString &fieldDataString)**\
 **virtual int**	**getFields(SoFieldList &resultList) const**\
 **virtual SoField \***	**getField(const SbName &fieldName) const**\
 **SbBool**	**getFieldName(const SoField \*field, SbName &fieldName) const**\
 **SbBool**	**isNotifyEnabled() const**\
 **SbBool**	**enableNotify(SbBool flag)**

Methods from class SoBase:

**void**	**ref()**\
 **void**	**unref() const**\
 **void**	**unrefNoDelete() const**\
 **void**	**touch()**\
 **virtual SoType**	**getTypeId() const**\
 **SbBool**	**isOfType(SoType type) const**\
 **virtual void**	**setName(const SbName &name)**\
 **virtual SbName**	**getName() const**

## DESCRIPTION

**This engine selects a single value from a multiple-value field, based on the input field index**. The type of the input field can be any subclass of **SoMField**, and the type of the output is the corresponding subclass of **SoSField**. For example, if the input type is **SoMFVec3f**, the output type will be **SoSFVec3f**. The type is specified when an instance of the class is created. For example, **SoSelectOne(SoMFFloat::getClassTypeId())**  creates an engine that selects one floating-point value.

Note that unlike most other engine fields, the **input** field and **output** are pointers. Note also that by default **input** does not contain any values, and no value is output from the engine.

## INPUTS

**SoSFInt32**	**index**\
 Index of the value to select from the multiple-value field.

**\<inputType\>**	**input**\
 The multiple-value field from which the value will be selected.

## OUTPUTS

**(\<outputType\>)**	**output**\
 The single value selected.

## METHODS

	**SoSelectOne(SoType inputType)**\
 Constructor. The argument specifies the type of the multiple-value input field.

## FILE FORMAT/DEFAULTS

```
SelectOne {
type	<inputType>
input	[]
index	0
}
```

## SEE ALSO

**SoEngineOutput, SoConcatenate, SoGate**