# Named varargs
**URL:** https://discuss.kotlinlang.org/t/named-varargs/16475
**Category:** Support
**Created:** [February 24, 2020, 7:09pm UTC](https://discuss.kotlinlang.org/t/named-varargs/16475 "2020-02-24T19:09:18Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@lucasqueiroz](https://discuss.kotlinlang.org/u/lucasqueiroz)
#### Post date: [February 24, 2020, 7:09pm UTC](https://discuss.kotlinlang.org/t/named-varargs/16475/1 "2020-02-24T19:09:18Z")
Is there any way to create “named varargs”, something close to Python’s kwargs?
To give a better context, I’m trying to create a “Factory” class, where I have a `build()` function that returns an instance of a data class. But I want to receive named arguments inside the build function to be able to override the default construction of the instance.
Example:
```auto
data class SampleEntity(
val id: Int,
val name: String
)
class SampleEntityFactory {
companion object {
fun build(kwargs: ): SampleEntity {
return SampleEntity(
id = kwargs.getOrDefault("id", 0),
name = kwargs.getOrDefault("name", "Foo Bar")
)
}
}
}
```
Is there any way I can achieve this, even if it is with a lib or reflection?
Thanks
---
### Author:  [@SackCastellon](https://discuss.kotlinlang.org/u/SackCastellon)
#### Post date: [February 24, 2020, 8:50pm UTC](https://discuss.kotlinlang.org/t/named-varargs/16475/2 "2020-02-24T20:50:37Z")
Why not adding all the parameters with default values?
```auto
data class SampleEntity(
val id: Int,
val name: String
)
class SampleEntityFactory {
companion object {
fun build(id: Int = 0, name: String = "Foo Bar"): SampleEntity {
return SampleEntity(
id = id,
name = name
)
}
}
}
```
But if you really want to use something like `kwargs` you could use a `Map` but you will lose type-safety
---
### Author:  [@lucasqueiroz](https://discuss.kotlinlang.org/u/lucasqueiroz)
#### Post date: [February 24, 2020, 9:16pm UTC](https://discuss.kotlinlang.org/t/named-varargs/16475/3 "2020-02-24T21:16:39Z")
It is a possibility, but then it doesn’t let me create a `BaseFactory` interface, where I could declare the `build()` function, and also it seems kinda repetitive, and when you have a data class with a lot of variables, the amount of parameters inside the `build()` function will be huge.
I was looking for something like the `copy` method that Kotlin implements, but I’m not sure if it is actually implemented somewhere (like an interface) or if the compiler creates the methods (Or other approaches).
---
### Author:  [@al3c](https://discuss.kotlinlang.org/u/al3c)
#### Post date: [February 24, 2020, 11:05pm UTC](https://discuss.kotlinlang.org/t/named-varargs/16475/4 "2020-02-24T23:05:04Z")
You could use reflection to invoke your constructor, and take a `Map`.
In general I’d discourage that as well as classes which have many constructor parameters, but I think that’s as close as you get. Obviously you won’t have compile time type checks.