Skip to main content

Coupling in borland C language

Coupling measures the strength of all relationships between functional units. It is the measure of the interdependence of one module to that of another. The program should have low coupling. Low coupling minimize the cause of errors in other modules. The errors in the other modules are caused because of the change in one module.

Definition: Coupling can be defined as the degree of interdependence between two or more modules. The reduction in coupling reduces the complexity of the program. While designing a program, make each module as independent as possible eliminating unnecessary relationships.

The following figure shows the types of coupling that exists in programming:
Types of Coupling:
1. No direct coupling
2. Normal coupling
    2.1   Data coupling
    2.2   Stamp coupling
    2.3   Control coupling
3. Common coupling
4. Content coupling

No direct coupling: These are the independent modules of the program. They are not really components of a single program.

Normal coupling: Two modules, X and Y, are normally coupled if X calls Y, Y returns to X and all information passed between them is by parameters in the call.

Data coupling: Two modules are said to be data coupled if they communicate by passing parameters. This is the most common type of coupling. Try to keep the parameters as minimum as possible.

Stamp coupling: Two modules are said to be stamp coupled if they communicate through a passed data structure that contains more information than necessary for them to perform their operations. A complete piece of data is passed between the modules.

Control coupling: Two modules are said to be control coupled if they communicate with the help of at least one "control flag". The control flag controls internal logic of the module.

Common coupling: Two modules are said to be common coupled if both of them share the same global data area. This type of coupling is really undesirable. Problem or error in one module can affect the other modules. Even it is difficult to identify the affected modules.

Content coupled: Two modules are content coupled if one module changes a statement in another, one module references or alters data contained inside another module or one module branches into another module.

The cohesion exists is within the modules where as the coupling exists between modules within the program. The law of program development is:

"Minimize the COUPLING and Maximize the COHESION"

Comments

Popular posts from this blog

difference between structure and union in C Language

In c language article we will see the difference between union and structure. Both are the user define datatype in c language. See the table which is mentioned below: ASP.NET Video Tutorial Series Structure Union1.The keywordstruct is used to define a structure 1. The keyword union is used to define a union. 2. When a variable is associated with a structure, the compiler allocates the memory for each member. The size of structure is greater than or equal to the sum ofsizes of its members. The smaller members may end with unused slack bytes. 2. When a variable is associated with a union, thecompiler allocates thememory by considering the size of the largest memory. So, size of union is equal to the size of largest member. 3. Each member within a structure is assigned unique storage area of location. 3. Memory allocated is shared by individual members of union. 4. The address of each member will be in ascending order This indicates that memory for each member will start at different offset v…

Difference between Linear search and Binary Search in c language

SQL Video Channel : Download all SQL Video



Binary Search Linear Search Works only on sorted items. such as  1,2,3,4,5,6  etc
Works on sorted as well as unsorted items. 12,4,5,3,2,1 etc Very efficient if the items are sorted Very efficient if the items are less and present in the beginning of the list. such as Suppose your list items are : 12,3,4,5,1 and you want to search 12 number then you get beginning in the list. Works well with arrays and not on linked lists. Works with arrays and linked lists.
Number of comparisons are less More number of comparisons are required if the items are present in the later part of the array or its elements are more.

Memory representation of Linked List Data Structures in C Language

Memory representation of Linked List

             In memory the linked list is stored in scattered cells (locations).The memory for each node is allocated dynamically means as and when required. So the Linked List can increase as per the user wish and the size is not fixed, it can vary.

               Suppose first node of linked list is allocated with an address 1008. Its graphical representation looks like the figure shown below:


      Suppose next node is allocated at an address 506, so the list becomes,



  Suppose next node is allocated with an address with an address 10,s the list become,


The other way to represent the linked list is as shown below:




 In the above representation the data stored in the linked list is “INDIA”, the information part of each node contains one character. The external pointer root points to first node’s address 1005. The link part of the node containing information I contains 1007, the address of next node. The last node …