A modern programming language that makes developers happier.

kotlinlang

Hello everyone. How can I serialize a `Map&lt;String, Any&gt;`?

You can serialize Any polymorphically: `Map&lt;String, @Polymorphic Any&gt;`. But I recommend you to choose more narrow scope of model. Probably you want `JsonElement`.

Ok thanks, I'll try it out and let you know if I have any problem :grin:

I have the following class:

```
@Serializable
data class TxMessage (
  val type: String, 
  val value: Map&lt;String, @Polymorphic Any&gt;
)
```

But when I try to serialize an instance of it I get

```
Exception in thread "DefaultDispatcher-worker-1" java.lang.NoSuchMethodError: kotlinx.serialization.PolymorphicSerializer: method &lt;init&gt;()V not found
	at TxMessage.write$Self(TxMessage.kt)
```

this is the test I'm running:


```
assertEquals(
    "{\"type\":\"myType\",\"value\":{\"first\":1,\"second\":\"second_value\",\"third\":3.3}}",
    Json.plain.stringify(TxMessage(
        type = "myType",
        value = mapOf(
            "first" to 1,
            "second" to "second_value",
            "third" to 3.3
        )
    ))
)
```

`kotlinx.serialization.PolymorphicSerializer: method &lt;init&gt;()V not found` happens when you're trying to use kotlin 1.3.21 with lib 0.11.0. please upgrade to 1.3.30