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		Traubenfuchs on May 2, 2025 \| parent \| context \| favorite \| on: Strings Just Got Faster How does the jvm know the map is immutable? But interned strings can also reuse their hashcode forever.

amiga386 on May 2, 2025 [–]

Map.of() promises to return an immutable map. new HashMap<>() does not.

https://docs.oracle.com/en/java/javase/17/docs/api/java.base...

How it tells the JVM this? It uses the internal annotation @jdk.internal.ValueBased

https://github.com/openjdk/jdk/blob/jdk-17-ga/src/java.base/...

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