3 ms·

Java arrays aren't (technically) in java.io, java.util, or java.lang

28 points by kmontrose 14y ago

euphoria83 14y ago
What is [I ?
- kmontrose 14y ago
  It's the class name for an integer array (int[]) in Java. There's code in the linked answer showing how to get at it.
  - drtse4 14y ago
    Additional info here: http://java.sun.com/docs/books/jni/html/types.html#70113 http://java.sun.com/docs/books/jni/html/types.html#70113
ExpiredLink 14y ago
Why should they?
- kmontrose 14y ago
  It's interesting, as they're a core language feature that isn't in the java.lang package. Obviously it's not harming anything that they're not.
  - wunderland 14y ago
    I don't understand. Didn't his test program output say that the superclass of the array class was java.lang.Object? I'm sorry if this is a stupid question. Doesn't that mean that arrays are in java.lang?
    - kmontrose 14y ago
      If you go high enough up the inheritance tree everything goes back to java.lang.Object, so no. If java arrays were something completely distinct from objects (like the primitive types are/were) that would have been interesting, which is what I was checking the super class for there.
joejohnson 14y ago
What does this mean? The first stable version was the JDK 1.0.2. is called Java 1
- kmontrose 14y ago
  That's straight out of wikipedia. http://en.wikipedia.org/wiki/Java_version_history#JDK_1.0_.28January_23.2C_1996.29 http://en.wikipedia.org/wiki/Java_version_history#JDK_1.0_.2... Java version naming is a bit confusing, especially retrospectively. Starting with the release of JDK 1.2 (which was the third release, after 1.0.2 and 1.1) Sun started referring to everything as Java 2 (J2SE, J2EE, etc.). Presumably this means that there were two releases of Java 1, JDKs 1.0.2 and 1.1. After JDK 1.4 (still Java 2) was Java 5.0, after that was Java 6 which dropped the Java 2 nomenclature (now different versions are just JSE, JEE, and so on).
  - joejohnson 14y ago
    Oh, thank you. I think it was the grammar error which threw me: The first stable version was the JDK 1.0.2. which is called Java 1
  - deleted 14y ago
    [deleted]
sehugg 14y ago
Yes, arrays are special. Which makes some people furious. http://c2.com/cgi/wiki?JavaArraysShouldBeFirstClassObjects http://c2.com/cgi/wiki?JavaArraysShouldBeFirstClassObjects

28 points by kmontrose 14y ago

euphoria83 14y ago

What is [I ?

kmontrose 14y ago
It's the class name for an integer array (int[]) in Java. There's code in the linked answer showing how to get at it.
- drtse4 14y ago
  Additional info here: http://java.sun.com/docs/books/jni/html/types.html#70113 http://java.sun.com/docs/books/jni/html/types.html#70113

ExpiredLink 14y ago

Why should they?

kmontrose 14y ago
It's interesting, as they're a core language feature that isn't in the java.lang package. Obviously it's not harming anything that they're not.
- wunderland 14y ago
  I don't understand. Didn't his test program output say that the superclass of the array class was java.lang.Object? I'm sorry if this is a stupid question. Doesn't that mean that arrays are in java.lang?
  - kmontrose 14y ago
    If you go high enough up the inheritance tree everything goes back to java.lang.Object, so no. If java arrays were something completely distinct from objects (like the primitive types are/were) that would have been interesting, which is what I was checking the super class for there.

joejohnson 14y ago

What does this mean? The first stable version was the JDK 1.0.2. is called Java 1

kmontrose 14y ago
That's straight out of wikipedia. http://en.wikipedia.org/wiki/Java_version_history#JDK_1.0_.28January_23.2C_1996.29 http://en.wikipedia.org/wiki/Java_version_history#JDK_1.0_.2... Java version naming is a bit confusing, especially retrospectively. Starting with the release of JDK 1.2 (which was the third release, after 1.0.2 and 1.1) Sun started referring to everything as Java 2 (J2SE, J2EE, etc.). Presumably this means that there were two releases of Java 1, JDKs 1.0.2 and 1.1. After JDK 1.4 (still Java 2) was Java 5.0, after that was Java 6 which dropped the Java 2 nomenclature (now different versions are just JSE, JEE, and so on).
- joejohnson 14y ago
  Oh, thank you. I think it was the grammar error which threw me: The first stable version was the JDK 1.0.2. which is called Java 1
- deleted 14y ago
  [deleted]

sehugg 14y ago

Yes, arrays are special. Which makes some people furious. http://c2.com/cgi/wiki?JavaArraysShouldBeFirstClassObjects http://c2.com/cgi/wiki?JavaArraysShouldBeFirstClassObjects