#JavaTraps

Java Traps #13 Static methods belong to the class, not the object so polymorphism doesn’t apply. Follow for more if this helped. #Java #JavaTraps #SoftwareEngineering #TechTwitter

Java Traps #7 Concurrent Modification The for-each loop is secretly using an iterator. When you modify the list directly, the loop and the collection go out of sync. Java fails fast and throws an exception to stop corrupt or unpredictable behaviour early. #Java #JavaTraps #SoftwareEngineering #TechTwitter

Java Traps #15 “Immutable” classes that aren’t actually immutable Your class can be final and still be mutable if it exposes or stores mutable objects incorrectly. final protects references, not data. Defensive copies = real immutability #Java #JavaTraps #SoftwareEngineering #TechTwitter

Java Traps #14 Synchronized on the wrong object synchronized only works if all threads lock the same object. If you lock on new Object(), every thread gets its own lock. So everyone thinks they’re synchronized but no one actually is. #Java #JavaTraps #TechTwitter #SoftwareEngineering

Java Traps #19 forEach() ≠ for loop forEach() can’t control flow like a normal loop, you can’t use break, continue, or return to stop iteration early. Follow for more such content. #Java #JavaTraps #SoftwareEngineering #TechTwitter

Java Traps #6 Floating Point Comparison Java can’t store some decimal numbers exactly, so math with doubles isn’t perfectly accurate. That’s why you compare them using a small tolerance instead of ==. #Java #JavaTraps #SoftwareEngineering

Java Traps #12 Fields Don’t Override In Java, fields are chosen at compile time using the reference type, while methods are chosen at runtime using the object type. Follow for more if this helped. #Java #JavaTraps #TechTwitter #SoftwareEngineering

Now I only know `% != mod`, and the negative input may lead to unexpected results. #Java #JavaTraps #JavaInterviewQuestions