Top-Down Programming Points : top-down programming, what is meant by top-down programming, how does top-down program work, disadvantages of top-down programming Top-Down Programming Top-down programming is the opposite of bottom up programming. It refers to the style of programming where an application is constructed starting with a high level description of what it is supposed to do and breaking the specification down into simpler pieces, until a level has been reached that correspond to the primitives of the programming language to be used. How does Top-down Program Work Top down programming (TDP) tends to generate modules that are based on functionally, usually in the form of functions or procedures typically the high level specification of the system states functionality. The high level- description is the refined to be a sequence or a loop of simpler function or procedures, that are then themselves redefine. In this style of programming there is a great risk that implementation details of many data structure have to be shared between modulus and this globally exposed. This in turn makes implementation details after thereby creating unwanted dependencies between different parts of the application. Disadvantages of Top-down Programming Top-down programming complicates testing further more top-down programming tends to generate modules that are very specific to the application that is being written thus not very re-usable but the main disadvantages of Top – down programming (TOP) is that all decision made from the start of the project depend directly or indirectly on the high level specification of the application. It is well known fact that this specification tends to change over time when that happens there is a great risk that large part of the application need to be rewritten.