# NavArgumentBuilder

Artifact: [androidx.navigation:navigation-common](https://developer.android.com/jetpack/androidx/releases/navigation) [View Source](https://cs.android.com/search?q=file:androidx/navigation/NavDestinationBuilder.kt+class:androidx.navigation.NavArgumentBuilder) Added in [2.4.0](https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0)

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Kotlin \|[Java](https://developer.android.com/reference/androidx/navigation/NavArgumentBuilder "View this page in Java") Common/AllAndroid/JVMJavaScript
- Cmn

  ```
  @NavDestinationDsl
  class NavArgumentBuilder
  ```

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DSL for constructing a new `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgument`

## Summary

| ### Public constructors |
|---|---|
| `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgumentBuilder#NavArgumentBuilder()()` | Cmn |

| ### Public functions |
|---|---|---|
| `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgument` | `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgumentBuilder#build()()` Builds the NavArgument by calling `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgument.Builder#build()`. | Cmn |

| ### Public properties |
|---|---|---|
| `https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-any/index.html?` | `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgumentBuilder#defaultValue()` An optional default value for this argument. | Cmn |
| `https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-boolean/index.html` | `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgumentBuilder#nullable()` Controls if this argument allows null values. | Cmn |
| `https://developer.android.com/reference/kotlin/androidx/navigation/NavType<*>` | `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgumentBuilder#type()` The NavType for this argument. | Cmn |

## Public constructors

### NavArgumentBuilder

Cmn Added in [2.4.0](https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0)

```
NavArgumentBuilder()
```

## Public functions

### build

Cmn Added in [2.4.0](https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0)

```
fun build(): NavArgument
```

Builds the NavArgument by calling `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgument.Builder#build()`.

## Public properties

### defaultValue

Cmn Added in [2.4.0](https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0)

```
var defaultValue: Any?
```

An optional default value for this argument.

Any object that you set here must be compatible with `https://developer.android.com/reference/kotlin/androidx/navigation/NavArgumentBuilder#type()`, if it was specified.

### nullable

Cmn Added in [2.4.0](https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0)

```
var nullable: Boolean
```

Controls if this argument allows null values.

### type

Cmn Added in [2.4.0](https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0)

```
var type: NavType<*>
```

The NavType for this argument.

If you don't set a type explicitly, it will be inferred from the default value of this argument.