Dale - Computer Science Illuminated 196

Dale - Computer Science Illuminated 196 - 6.3...

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6.3 Object-Oriented Design 169 oriented view of design, the algorithms for carrying out responsibilities tend to be fairly short. For example, the knowledge responsibilities usually just return the contents of one of an object’s variables, or send a message to another object to retrieve it. Action responsibilities are a little more complicated, often involving calculations. Thus, the top-down method of designing an algorithm is usually appropriate for designing responsibility algorithms. Final Word To summarize, top-down design methods focus on the process of trans- forming the input into the output, resulting in a hierarchy of tasks. Object- oriented design focuses on the data objects that are to be transformed, resulting in a hierarchy of objects. Grady Booch puts it this way: “Read the specification of the software you want to build. Underline the verbs if you are after procedural code, the nouns if you aim for an object-oriented program.” 6 We propose that you circle the nouns and underline the verbs. The
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This note was uploaded on 01/13/2011 for the course CSE 1550 taught by Professor Marianakant during the Fall '10 term at York University.

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