I am currently studying for a Java certification and I keep seeing the terms "access modifier" and "access specifier" used interchangeably in various textbooks. Is there a formal architectural distinction between these two in the Java Language Specification, or are they just different names for public, private, protected, and default? I want to make sure I am using the correct terminology during technical interviews for Software Development roles.
3 answers
Strictly speaking, in the context of Java, the term "Access Modifier" is the official terminology used in the Java Language Specification (JLS). While languages like C++ frequently use "Access Specifier," Java developers and the official documentation refer to public, protected, and private as modifiers. These keywords define the scope of visibility for classes, methods, and variables. There is also a fourth level called "default" (or package-private), which is not an explicit keyword but is the behavior when no modifier is present. Understanding this is key for encapsulation, as it dictates how different components of your software architecture interact across packages.
Does the Java compiler treat the "default" access level differently in terms of bytecode generation compared to the explicit modifiers like public or private, or is it simply a lack of a flag in the metadata?
In most interviews, if you say "modifier," you're safe. Most people use "specifier" because they come from a C++ background, but Java's official docs always use the word "modifier."
I agree with Robert. I’ve interviewed many candidates, and while I wouldn't penalize someone for saying "specifier," using the term "modifier" shows you’ve really spent time with the official Java documentation.
That is a deep dive, Christopher! In the JVM bytecode, there actually isn't a specific flag for "default" access. Instead, the absence of the ACC_PUBLIC, ACC_PRIVATE, and ACC_PROTECTED flags tells the JVM that the member is package-private. So, while we call it an access level in our Java code, it's essentially the "zero-value" state of the access flags in the compiled class file.