Glossary

Modifiers

TL;DR

Modifiers are keywords in programming languages that control the access level, behavior, and properties of classes, methods, variables, and other program elements, determining how they can be used and accessed within a software application.

Concept

Modifiers are special keywords used in programming languages to alter the properties and behavior of program elements such as classes, methods, variables, and constructors. They define important characteristics like access control, inheritance rules, and runtime behavior.

Common types of modifiers include:

  1. Access Modifiers: Control the visibility and accessibility of program elements:

    • Public: Accessible from anywhere in the application
    • Private: Accessible only within the same class
    • Protected: Accessible within the same class and its subclasses
    • Internal/Package: Accessible only within the same package or module

  2. Non-Access Modifiers: Define additional properties and behavior:

    • Static: Belongs to the class rather than instances
    • Final/Const: Cannot be modified after initialization
    • Abstract: Must be implemented by subclasses
    • Synchronized: Thread-safe access control
    • Volatile: Value may be modified by different threads

  3. Inheritance Modifiers: Control class and method inheritance:

    • Virtual: Can be overridden by subclasses
    • Override: Replaces parent class implementation
    • Sealed/Final: Cannot be subclassed or overridden

Modifiers play a crucial role in object-oriented programming by enforcing encapsulation, ensuring proper access control, and defining the lifecycle and behavior of program elements. They help developers create secure, maintainable, and well-structured code by clearly defining the intended use and limitations of each component.

Related words: Coroutines Backwards Compatible Breaking Change