passing code with behavior parameterization

Behavior parameterization is a programming technique that allows a method’s behavior to be defined at runtime rather than being hard-coded. Instead of writing multiple versions of the same logic, we pass the behavior itself as a parameter, making the code more flexible, reusable, and easier to evolve. In Java, this idea existed even before Java 8 through interfaces and anonymous classes, but it became significantly more powerful and readable with the introduction of lambda expressions and functional interfaces. By parameterizing behavior, we can separate what a method does from how it does it, leading to cleaner APIs and better abstraction. This article focuses on understanding the concept of passing code as behavior, why it matters, and how it laid the foundation for modern Java features such as lambdas, streams, and functional-style programming.