SayPro Top-Down versus Bottom-Up

Top-Down programming is about writing the business logic first in pseudocode or non-compiling code and then working down to the specifics, and it’s the first program design technique taught in schools. Let’s say that you’re designing a coin-counting program, and you write what you want the perfect main () to look like:The program doesn’t compile yet, but you’ve now defined the essence of the program in one place. With top-down programming you start like this and then you focus on defining what’s going on in the CoinHopper class and what abstraction is going on in the Output class.Bottom-up programming is the natural opposite, where the programmer intuits that he’ll need a way to control the coin counting hardware and begins writing the code for that before writing the code for main(). One of the reasons for doing it this way is to discover non-obvious requirements that have a major impact on the high-level design of the program. Lets say that when we dig into the nitty-gritty of the API for the hardware we discover that it doesn’t tell us what type of coin is there, it just gives us sensory readings like the diameter and weight. Now we need to change the design of the program to include a module that identifies coins by their measurements.What usually happens in the real-world is that all of the top-down design is done on paper and the actual coding goes bottom-up. Then when the coding effort falsifies an assumption made on paper the high-level design is easier to change."A further disadvantage of the top-down method is that, if an understanding of a fault is obtained, a simple fix, such as a new shape for the turbine housing, may be impossible to implement without a redesign of the entire engine." – from Richard Feynman’s report of the Space Shuttle Challenger DisasterPlease visit our website at www.saypro.online Email: info@sayro.online Call: + 27 (0) 11 071 1903 Email: info@saypro.online Tel: + 27 11 071 1903 WhatsApp: + 27 84 313 7407. Comment below for any questions and feedback. For SayPro Courses, SayPro Jobs, SayPro Community Development, SayPro Products, SayPro Services, SayPro Consulting, and SayPro Advisory visit our website to www.saypro.online