Solutions
Multiplatform
Server-side
Data science
Android
Case studies
Docs
Language guide
Multiplatform development
API
APIs overview
Standard library (stdlib)
Test library (kotlin.test)
Coroutines (kotlinx.coroutines)
Serialization (kotlinx.serialization)
Kotlin I/O library (kotlinx-io)
Date and time (kotlinx-datetime)
JVM Metadata (kotlin-metadata-jvm)
Kotlin Gradle plugins
Ktor
Compose Multiplatform Material3
Community
Teach
Play
Playground
Koans
Kotlin libraries
Toggle table of contents
2.4
Select version
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
JS
Platform filter
JS
Switch theme
Search in API
Kotlin libraries
kotlin-stdlib
/
kotlin.js
/
Date
/
LocaleOptions
/
era
era
JS
abstract
external
var
era
:
String
?
(
source
)
Since Kotlin
1.1
Thanks for your feedback!
Was this page helpful?
Yes
No
How can we improve?
Enter your name and email address if you would like to receive a follow-up message or
contact our support
.
By submitting this form, I agree that JetBrains s.r.o. ("JetBrains") may use my name, email address, phone number, and country of residence to provide support. I agree that JetBrains may process said data using
third-party services
for this purpose in accordance with the
JetBrains Privacy Policy
.