Explain the difference between a top-down approach and a bottom-up approach in programming. 5m Jun 2010
|A top-down approach is essentially the breaking down of a program to gain insight into its compositional small program (or module) in a reverse engineering fashion.||A bottom-up approach is the piecing together of module (or small program) to give rise to more complex program, thus making the original modules of the emergent program.|
|Structure / procedure oriented programming languages like C programming language follows top-down approach.||Object oriented programming languages like C++ and JAVA programming language follows bottom-up approach.|
|A top-down approach begins with high level design and ends with low level design or development.||A bottom-up approach begins with low level design or development and ends with high level design.|
|In top-down approach, main function is written first and all sub functions are called from main function thus, sub-functions are written based on the requirement||In bottom-up approach, code is developed from modules and then these modules are integrated with main function|
Now-a-days, both approachs are combined together and followed in modern software design.