Fine & Shine Difference Between Top Down and Bottom Up Approach

Pick Your Approach Developers

So, hello, dear programmers, today in this post we are going to study a very interesting topic. If you have always been confused that whether you should adopt the top down or bottom up approach in the structure of your project. Then, this article will give you a brief comparison between both the terms with the helpful conclusion.

Okay, so when we are talking about computer programming, then the algorithm on which the complexed programs are designed and controlled is mainly based on the two different approaches. So, before evaluating the difference between both terms, let’s check out the basic definition of both the approaches.

Top-Down Approach. In this approach, complex algorithm or a problem is broken down into the smaller segments called modules, the process is called as modularization. These modules are further decomposed into the smaller parts until there is no space left for breaking. So, basically, top-down approach means breaking the problem into smaller modules and then organizing into systematic manner to solve it.

Bottom-Up Approach. In this approach, everything works differently. Here developers start solving the problem from the most basic level and then moves upward in the conjugation of several parts of the solution to get the required result. The modules and sub-modules are designed and solved separately. This approach works in different layers. Each module designed is tested at a fundamental level that means unit testing is done before the integration of the individual modules to get a solution.

So, let’s check out how the comparative strategies of both the approaches work.

Difference Between Top-down & Bottom-Up Approach

  1.    Modules. In the top-down approach, modules are divided into smaller units and then solve it. In the bottom-up approach, the problem starts to solve up from the smaller modules and adding them up together goes up.
  2.    Redundancy. Top-down approach contains redundant information. On the contrary, redundancy can be easily eliminated from the bottom up approach.
  3.    Communication. In the top-down approach, a well-structured communication is not necessary. The workflow can be easily maintained without establishing a proper communication channel, whereas in the bottom-up approach strong communication among each step is mandatory.
  4.    Analyzed. The individual modules are perfectly analyzed at every step in the top-down approach which makes this approach very useful. But, work on the bottom-up approach is based on the data hiding and encapsulation.
  5.    Structure. The structural programming languages such as C uses the top-down approach. Whereas OOP languages like C++ and Java shows interest in the bottom-up approach.
  6.    Relation. To solve the problem in the top approach relationship among the modules is not always essential. But, on the other hand, without defining the relationship between modules for better communication and working, no problem can be handled in a bottom approach.
  7.    Uses. The top-down approach is used in the implementation, testing, debugging and module documentation of the code. However, in a bottom-up approach, it is only used in testing the code.

Conclusion

So, after studying the difference between both the approaches, we have concluded a few things. First, a top-down approach is the conventional approach which decomposes the higher system into the lower system. However, the bottom-up approach means dealing at the lower level first and then going higher for better efficiency.

That’s why considering the few points as modules in top-down approach aren’t connected in a manner so that they can communicate well and the feature of hiding information, we vote in the favor of a bottom-up approach.  If you disagree with our conclusion, then please comment and share your reasons.

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