Question

Why is is useful to enforce the separation of interface from implementation (i.e., the abstraction

boundary) of an ADT? Provide a concrete example to help justify your explanation

Answer 1

It is useful to enforce, thanks to these points:

• Majority of the program becomes independent of the abstract data type's representation, in order that representation may be improved without breaking the complete program.
• Thanks to the separation of interface from implementation, the different parts of a program become less dependent on other parts and on how those other parts are implemented.
• It becomes easier for every part of a program to use an implementation of its data types which will be more efficient for that specific part of the program.

Real life Example: Mobile Phones

Abstract view

• 6 GB RAM
• Snapdragon 845
• 6.5 inch Super Amoled Screen
• Quad Camera
• Android Pie

Call(), Timer(), Calculator(), Camera(), Video(), Voice_Recorder()

Implementation View

Class mobilePhones{

private:

int ramSize;

string processorName;

float screenType;

int cameraCount;

string androidVersion;

public:

void call();

void timer();

void calculator();

void camera();

void video();

void voice_recorder();

};

Overall, the separation of data structures and operations and the constraint to only access the data structure via a well-defined interface allows to choose data structures appropriate for the application environment.