A class with high cohesion is focused on what it does, its specific to what it does. Originally Answered: what is cohesion and coupling in java ? Cohesion refers to what a class does. loose coupling is a better choice because A loosely coupled will help you when your application need to change or grow. In general, Tight Coupling is bad in but most of the time, because it reduces flexibility and re-usability of code, it makes changes much more difficult, it impedes test ability etc. While creating, you should aim for low coupling, i.e., dependency among modules should be less. Cohesion shows the module's relative functional strength. Coupling shows the relative independence between the modules. Having private fields, non-public classes and private methods provide loose-coupling, while making all members visible within the class and having package as the default visibility provide high cohesion.Cohesion shows the relationship within the module. In other words, loose coupling and strong cohesion provides the best software. In order to have the best quality software, cohesion and coupling should reach the two opposite ends of their spectrums. Cohesion talks about how much the functionality are related to each other within the module, while coupling deals with how much one module is dependent on the other program modules within the whole application. What is the difference between Coupling and Cohesion?Įven though coupling and cohesion deal with the quality of a module in software engineering, they are entirely different concepts. It is also possible to have some coupling to help objects interact with each other without hampering its scalability and flexibility. But it is recommended that the programmers give their best effort to reduce the coupling as much as possible.
However, in programming languages like Java, completely avoiding coupling is impossible. Strong coupling always leads to programs with low flexibility and less scalability/extensibility.
#COHESION AND COUPLING IN SOFTWARE ENGINEERING PPT CODE#
This is a nightmare when the code is modified, because high coupling means that the programmers need to work on several places of code for even a single behavioral modification. Strong coupling is never good because one object can be highly dependent on some other object. Loosely-coupled programs are high in flexibility and extensibility. Interactions between two objects occur because there is coupling. Maintaining, modifying and extending behaviors scattered all over the code is very tedious even for the most experience programmers.Ĭoupling measures how much each of the program modules are dependent on the other program modules. It’s just that without cohesion, it will be very difficult to mange the functionality because they will be scattered in many wrong places as the complexity of the application increases over time. It is important to understand that not having cohesiveness does not mean that the overall application does not have the required functionality. On the other hand, if a class is performing a bunch of totally unrelated functionalities that means the class is not cohesive at all. If a certain class is performing a set of highly related functions, that class is said to be cohesive. Well structured classes lead to highly cohesive programs. These two software engineering metrics were developed by Larry Constantine to reduce the cost of modifying and maintaining software.Ĭohesion measures how strongly each of the functions are related within a program module. Actually, any object oriented language (including Java) has the two main objectives of increasing cohesiveness and decreasing the coupling at the same time, in order to develop most efficient programmes.
Cohesion measures how strongly each of the functions are related within a module.
Coupling measures how much each of the program modules are dependent on the other program modules. Coupling and cohesion are two concepts found in Java (and all other object oriented languages).