## How are Interfaces Represented in Go: Static vs. Dynamic Perspectives?

Understanding Interface Representation in Go

Question:

Understanding the representation of interfaces in Go often raises confusion. One article claims that an interface variable stores the value and its actual type, while another suggests that it represents only the static interface type. Where lies the discrepancy?

Explanation:

The two mentioned articles approach interface representation from different perspectives. The article on "Laws of Reflection" provides an overview of how objects are examined through reflection, focusing on the (value, type) pair representation. On the other hand, the second article analyzes the dynamic dispatch properties of an interface and its resolution at runtime.

Runtime Interface Behavior:

According to the second article, an interface at runtime is essentially a "wrapper object." It stores information about the wrapped object, which helps determine where to dispatch function calls in the object's implementation. This wrapper object does not contain all the methods implemented by the underlying type.

Static Interface Representation:

In contrast, the first article describes the static representation of an interface variable. When assigning an os.File value to an io.Reader variable (var r io.Reader), r contains the actual value (tty) and its real type (*os.File). This is the static type of r.

Interface Usage:

Despite the different representations, both perspectives emphasize the ability to access methods through an interface at runtime. When calling Read on r, the interface wrapper object directs the call to the appropriate method in the os.File type, ensuring that methods are resolved dynamically.

Reflection's Role:

Reflection allows developers to inspect objects at the most granular level. Through the reflect.ValueOf and reflect.TypeOf methods, reflection provides a simple representation of the interface as a (value, type) pair, making it easy to understand its static properties.

The above is the detailed content of ## How are Interfaces Represented in Go: Static vs. Dynamic Perspectives?. For more information, please follow other related articles on the PHP Chinese website!