In this tutorial, we will learn about Interface Segregation Principle.It is one of the SOLID principles. The goal of the interface segregation principle is similar to the single responsibility principle. 5. Here is the list of the blogs in this series: Understand SOLID Principle; Single Responsibility Principle Dependency Inversion Principle The principle states: High-level modules should not depend on low-level modules. Clients should not be forced to implement interfaces they do not use. Instead of one fat interface many small interfaces are preferred based on groups of methods, each one serving one submodule. As a result, when an interface method changes, any clients that don't use that method should not change. For example, the Collection interface in Java has many methods like size() and isEmpty() which are often used together, so it makes sense for them to be in a single interface. The Interface Segregation Principle states that clients should not be forced to implement interfaces they don't use. In this article, I am going to discuss the Interface Segregation Principle with a real-time example.The letter I in the SOLID Design Principle stands for Interface Segregation Principle which is also known as ISP.. Both should depend on abstractions. Make fine grained interfaces that are client specific. According Robert Martin's Agile Software Development: Principles, Patterns and Practices, the principle is defined as, “Clients should not be forced to depend on methods that they do not use.” In other words, classes should not have access to behavior it does not use. The interface segregation principle means that interfaces that are too "thick" must be divided into smaller, more specific ones, so that clients using small interfaces know only about the methods they need for their work. Let's understand the principle through an example. Interface Segregation Principle states “Clients should not be forced to depend upon interfaces that they do not use.” Robert Martin has a very good explanation of Interface segregation principle (ISP), in his book "UML for Java Programmers". The interface segregation principle is the I in SOLID principles. THE INTERFACE SEGREGATION PRINCIPLE. Based on that, I don't think ISP is about an interface being "focused" on one logical, coherent group of things. The ISP states that no client should be forced to depend on methods it does not use. The Interface Segregation Principle and Other Solid Principles. Table Of Contents What are SOLID Principles Single Responsibility Principle Open Closed Principle Liskov's Substitution Principle Interface Segregation Principle Dependency Inversion Principle 5 java class design principles Introduction to SOLID Principles. Clients should not be forced to depend upon interfaces that they don't use. 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