What are coupling and cohesion?

What are coupling and cohesion?

What are coupling and cohesion?

Coupling

• The degree of dependency between the component is called coupling.
• If the dependency is more then it is considered as tightly coupling and dependency are less then it is considered as loosely coupling.
  

  Example

  Class A{ static int i=B.j }

  Class B{ Static int j=C.k }

  Class C{ static int k=D.m1(); }

  Class D{ public static int m1(){ return 10; }

• The above component are said to be tightly coupled with each other because dependency between component is more.
• Tightly coupling is not a good programming practice because it has several serious disadvantages.
  1. Without effective remaining component we can’t modify any component and hence enchantment becomes difficult.
  2. It suppresses reusability.
  3. It reduces maintainability of the application.
• Hence we have to maintain dependency between the component as less as possible i.e. Loosely coupling is good programming practice.
• The degree to which one class knows about another class”. If one class uses another class, that is coupling. Coupling is everywhere, but the level of coupling varies.
• Coupling refers to the degree to which one class knows about another, or makes use of another classes’ members.