Java Equality Operators (== and !=): How They Work With Primitives and Objects

Java's equality operators (== and !=) are widely used to compare values and always return a boolean result. Unlike relational operators, they support all primitive types including boolean, and Java performs numeric promotion when comparing mixed types such as char and double. For objects, == does not compare content but instead checks whether two references point to the same memory location. The compiler only permits object reference comparisons when the two types share a compatible inheritance relationship, throwing a compile-time error for unrelated classes. These behaviors are a common source of confusion for beginners and frequently appear in Java technical interviews.