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If you actually understand Java, you'll understand why this is wrong. Only newbies have confusion about this, most of which dissipates when you actually learn t

by junon 5y ago

If you actually understand Java, you'll understand why this is wrong. Only newbies have confusion about this, most of which dissipates when you actually learn the language you're working with. Tired of this 20+ year old "flaw" being used as cannon fodder.

dtech 5y ago
Just because something is a well known-flaw doesn't make it a glaring flaw. There's a reason newer JVM languages like Kotlin use == as an alias for equals instead of reference equality.
- marginalia_nu 5y ago
  What if you are interested in reference equality?
  - __float 5y ago
    In practice, how often are you interested in it? C# has `Object.referenceEquals()` because you _may_ want this sometimes. But to have reference equality be the default for something like `==` is a design flaw. Not one that can be fixed now, of course, but it will continue to cause bugs for years to come. Sometimes, it happens in core Java libraries themselves: https://bugs.openjdk.java.net/browse/JDK-8274779 https://bugs.openjdk.java.net/browse/JDK-8274779 https://github.com/openjdk/jdk/blob/722d639fad2e4fc6eb2aabd427e2719501899cfe/src/java.base/share/classes/sun/net/www/http/HttpClient.java#L310 https://github.com/openjdk/jdk/blob/722d639fad2e4fc6eb2aabd4...
    - marginalia_nu 5y ago
      Dunno, I do a fair bit of low level java work, happens every once in a while. Curiously, I don't do a lot of value-comparisons. Based on grepping in the repo for my search engine, I appear to do one every 1000 lines of code. May just be how I write code though. Some people seem to do that a lot more.
  - LordDragonfang 5y ago
    Python uses the `is` operator, which is semantically much more explicit (and arguably correct, though C#'s use of the `is` operator is probably more correct). edit: Kotlin uses `===`, which is another good option.
    - marginalia_nu 5y ago
      === seems almost more dangerous. It's a lot easier to tell == from Objects.equals(a,b) than == from ===.
      - wiseowise 5y ago
        Seriously?
        marginalia_nu 5y ago
        Yes. Look, languages are moving away from permitting constructs like "if (x = 1)" because it's difficult to distinguish from "if (x == 1)". Adding "if (x === 1)" into the mix is arguably a step backwards in terms of clarity.
Banana699 5y ago
This is like saying that null references are a non-issue because it have been there since the 1970s and that "true" $LANGUAGE developers never collide head-first into invalid dereferences. If something is ridiculous and un-ergonomic, it stays ridiculous and un-ergonomic no matter what. Reference comparison by default is ridiculous and un-ergonomic.
- junon 5y ago
  Null references exist in every language with the concept of null. It has nothing to do with Java specifically, and Java gives you a lot of information to debug them.
  - jraph 5y ago
    That's right, but that also doesn't answer the parent's point to which I fully agree.

by junon 5y ago

dtech 5y ago

Just because something is a well known-flaw doesn't make it a glaring flaw. There's a reason newer JVM languages like Kotlin use == as an alias for equals instead of reference equality.

marginalia_nu 5y ago
What if you are interested in reference equality?
- __float 5y ago
  In practice, how often are you interested in it? C# has `Object.referenceEquals()` because you _may_ want this sometimes. But to have reference equality be the default for something like `==` is a design flaw. Not one that can be fixed now, of course, but it will continue to cause bugs for years to come. Sometimes, it happens in core Java libraries themselves: https://bugs.openjdk.java.net/browse/JDK-8274779 https://bugs.openjdk.java.net/browse/JDK-8274779 https://github.com/openjdk/jdk/blob/722d639fad2e4fc6eb2aabd427e2719501899cfe/src/java.base/share/classes/sun/net/www/http/HttpClient.java#L310 https://github.com/openjdk/jdk/blob/722d639fad2e4fc6eb2aabd4...
  - marginalia_nu 5y ago
    Dunno, I do a fair bit of low level java work, happens every once in a while. Curiously, I don't do a lot of value-comparisons. Based on grepping in the repo for my search engine, I appear to do one every 1000 lines of code. May just be how I write code though. Some people seem to do that a lot more.
- LordDragonfang 5y ago
  Python uses the `is` operator, which is semantically much more explicit (and arguably correct, though C#'s use of the `is` operator is probably more correct). edit: Kotlin uses `===`, which is another good option.
  - marginalia_nu 5y ago
    === seems almost more dangerous. It's a lot easier to tell == from Objects.equals(a,b) than == from ===.
    - wiseowise 5y ago
      Seriously?
      - marginalia_nu 5y ago
        Yes. Look, languages are moving away from permitting constructs like "if (x = 1)" because it's difficult to distinguish from "if (x == 1)". Adding "if (x === 1)" into the mix is arguably a step backwards in terms of clarity.

Banana699 5y ago

This is like saying that null references are a non-issue because it have been there since the 1970s and that "true" $LANGUAGE developers never collide head-first into invalid dereferences. If something is ridiculous and un-ergonomic, it stays ridiculous and un-ergonomic no matter what. Reference comparison by default is ridiculous and un-ergonomic.

junon 5y ago
Null references exist in every language with the concept of null. It has nothing to do with Java specifically, and Java gives you a lot of information to debug them.
- jraph 5y ago
  That's right, but that also doesn't answer the parent's point to which I fully agree.