类型不匹配：推断类型是字符串？ 但预计字符串 kotlin

Question

I got error message:

AddAddressActivity.kt: (69, 53): Type mismatch: inferred type is String? but String was expected

Answer 1

This is because the getString method returns a nullable value ( String? ) but you are assigning it to something that takes a non-null value (expects String ). If you want to fix it you could assign it to a default string if it is null like this

val villageId = getString("village_id") ?: "default"

or to an empty string

val villageId = getString("village_id").orEmpty()

Answer 2

This is due to your villageId can be null which you have got from getString("village_id")

for solving this you can use default value so when bundle don't contains the provided key it will eventually returns the default value.

val villageId = getString("village_id", "My Default Value")

or you can use kotlin elvis to get other value when it's null.

val villageId = getString("village_id") ?: "My Default Value"

or if you're sure that intent will always contain the village id then you can use !!(not-null assertion operator) which will convert non-null value if not null else will throw exception

val villageId: String = getString("village_id")!!

you can more read about null safety in following link Null safety | Kotlin