| 1 | What are the eight primitive data types in Java, and how do they differ fundamentally from reference types like String or a custom class? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Beginner |
| 2 | What is the difference between the ++ (increment) and -- (decrement) operators used in prefix versus postfix position, and what subtle bug can arise from using them within a complex expression? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Intermediate |
| 3 | How does Java's short-circuit evaluation for && and || operators differ from the non-short-circuiting & and | operators when applied to boolean operands, and why does this distinction matter for avoiding NullPointerException? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Intermediate |
| 4 | How does Java's implicit numeric type promotion and narrowing/widening conversion rules work, and what specific data-loss or precision risks does an implicit narrowing conversion (requiring an explicit cast) guard against? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Advanced |
| 5 | How does Java's String immutability, combined with the string pool, interact with security-sensitive code (like handling passwords), and why is char[] generally recommended over String for storing sensitive data temporarily in memory? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Advanced |
| 6 | How does Java's compound assignment operator (like +=) implicitly include a narrowing cast that a corresponding explicit expanded assignment (x = x + y) does not, and what surprising behavior results from this? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Advanced |
| 7 | What is the difference between the == operator and the .equals() method when comparing two custom objects, if the class hasn't overridden equals()? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Beginner |
| 8 | How does Java's operator precedence and associativity determine the evaluation order of a complex expression, and what are some common precedence-related mistakes? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Intermediate |
| 9 | What is the difference between the == operator and the .equals() method when comparing String objects, and why does String's string pool (interning) behavior sometimes make == appear to 'work' for strings? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Intermediate |
| 10 | What is the difference between a Java text block (introduced as a standard feature in Java 15) and a traditional String literal, and what specific syntax rules govern indentation handling? Java › Java Fundamentals: Syntax, Data Types & Operators | Java | Java Fundamentals: Syntax, Data Types & Operators | Intermediate |