Hi all Could someone please tell me, how can I mak...

# getting-started

[zero_coding]

Hi all
Could someone please tell me, how can I make the following code more elegant:

class GenderMapper(val id: String, val description: String)

fun GenderMapper.toGender(): Gender {
    val description = this.description
    return Gender.new(id) {
        this.description = description
    }
}

[jbnizet]

You can use

return Gender.new(id) {
        this.description = [e-mail]
    }

[zero_coding]

Could you please explain the code

[zero_coding]

what does this@toGender means?

[Tobias Berger]

It tells the compiler which this you mean. in the lambda scope you have multiple this values available:
1. in the lambda, which seems to be defined as Gender.() -> Gender you have the Gender object as this
2. in the extension function scope you have the GenderMapper object.
If you just write this it will default to the innermost context. But Kotlin also allows you to access the other scopes. Each scope is given a name, which is by default the method name that comes right before you open the block. So when setting the description here, this givey sou the Gender and this@toGender gives you the GenderMapper.
This naming mechanism can also be used for returning out of lambdas (assuming you're working with inline functions). E.g. if you're inside a lambda for a call inside a forEach loop and want to jump out of this loop run (like continue, you can return@forEach.
If things get too complicated, you can also give each scope a different name like this:

myMultilevelList.forEach outerLoop@{ innerList ->
    innerList.forEach {
       if (it.hasError) return@outerLoop
    }
}

[Tobias Berger]

About your original question: If you have control over the GenderMapper class, I'd suggest putting description in the constructor/`new` function.

[zero_coding]

@Tobias Berger Could you please show me, how to do it?