The Interface Segregation Principle (ISP) is a design principle in computer science, introduced by Robert Martin as part of the SOLID principles of software design. It states that clients should not be forced to depend on interfaces they do not use.
In other words, the ISP is a principle of object-oriented programming, which states that a class should not be forced to implement interfaces it does not use. This helps to reduce the coupling between objects and makes the code easier to maintain and modify.
The ISP encourages the creation of small, focused interfaces, rather than large, generic ones. By breaking down the interfaces into smaller, more specialized pieces, the code becomes easier to understand and modify, as the responsibilities of each interface are clearly defined.
For example, instead of creating a single, large interface that defines all the methods that a class must implement, it is better to break down the interface into smaller, more focused pieces, such as an interface for reading data, and another for writing data. This way, classes that only need to read data are not forced to implement methods for writing data, and vice versa.
To follow the ISP, it is important to identify the smallest set of methods that are required for a particular use case, and to define the interfaces accordingly. This helps to reduce the coupling between objects and makes the code easier to maintain and modify.
In summary, the Interface Segregation Principle is a design pattern that helps to reduce coupling between objects, by ensuring that clients are not forced to depend on interfaces they do not use. This makes the code easier to understand, test, and modify, and improves the overall quality of the code.