Program Complexity Analysis Questions Long
In the context of program complexity, coupling and cohesion are two important concepts that help in understanding the organization and structure of a program.
Coupling refers to the degree of interdependence between different modules or components within a program. It measures how closely one module is connected to another module. A high degree of coupling means that modules are tightly interconnected, while a low degree of coupling indicates loose connections between modules. Coupling can be classified into different types:
1. Content Coupling: This occurs when one module directly accesses or modifies the content of another module. It is considered the strongest form of coupling and should be avoided as it leads to high interdependence and reduces the flexibility and maintainability of the program.
2. Common Coupling: In this type of coupling, multiple modules share a common data element or global variable. Changes to this shared data can affect multiple modules, making it difficult to understand and modify the program.
3. Control Coupling: Control coupling occurs when one module passes control information, such as flags or status variables, to another module. This type of coupling can make the program harder to understand and maintain as it requires tracking the flow of control between modules.
4. Stamp Coupling: Stamp coupling happens when modules share a composite data structure, such as a record or an object. Changes to the structure can impact multiple modules, leading to increased complexity.
5. Data Coupling: Data coupling is the most desirable form of coupling. It occurs when modules communicate by passing data through parameters or arguments. This type of coupling reduces interdependence and makes the program more modular and easier to understand and modify.
On the other hand, cohesion refers to the degree to which the responsibilities and tasks within a module are related and focused. It measures how well a module performs a single, well-defined function. High cohesion means that a module has a clear and specific purpose, while low cohesion indicates that a module performs multiple unrelated tasks. Cohesion can be classified into different types:
1. Functional Cohesion: This is the most desirable form of cohesion. It occurs when all the tasks within a module are related and contribute to a single well-defined function. Modules with high functional cohesion are easier to understand, test, and maintain.
2. Sequential Cohesion: In this type of cohesion, the tasks within a module are related and executed in a specific sequence. However, they may not contribute to a single well-defined function. Sequential cohesion can lead to less modular and more complex programs.
3. Communicational Cohesion: Communicational cohesion occurs when tasks within a module operate on the same data or share intermediate results. While this type of cohesion is better than sequential cohesion, it can still lead to increased complexity and interdependence.
4. Procedural Cohesion: Procedural cohesion happens when tasks within a module are grouped together based on their proximity in the code, rather than their logical relationship. This type of cohesion can make the program harder to understand and maintain.
5. Temporal Cohesion: Temporal cohesion occurs when tasks within a module are grouped together because they need to be executed at the same time. This type of cohesion can lead to less modular and more complex programs.
In summary, coupling and cohesion are two important concepts in program complexity analysis. Coupling measures the interdependence between modules, while cohesion measures the relatedness and focus of tasks within a module. High cohesion and low coupling are desirable as they lead to more modular, maintainable, and understandable programs.