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So let's look at the object-oriented analysis in a
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little more detail. As I said earlier, traditional analysis
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and design techniques were functionally oriented. What that means
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is that they concentrated on the functions to be performed,
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whereas the data upon which the functions operated were
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secondary to the functions themselves. Conversely, object oriented analysis, is
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primarily concerned that with a data objects, so we
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went from a functional oriented view to a data oriented
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view, what that means is that during the analysis phase,
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we define a system first in terms of the data
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types and their relationships, and the functions or methods are
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defined only later and associated with specific objects which are sets
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of data. So let's see how we can perform object
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orientated analysis in practice, so the basic idea is to be
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focused on the objects of the real world. So to
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go from a real world objects to a set of requirements.
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And we can describe this as a four-step process. The first
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step is to obtain or prepare a textual description of the
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problem to be solved. So obviously, we need to start from
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some description of the system that we need to build. And
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this is a very practical oriented approach, so that the next
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thing we do is that we take the description and we
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underline nouns. In this description. And the nouns that we underline
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will become classes in my analysis. We then look at adjectives in
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the document. We underline those, and we use that
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information to identify the attributes of the classes that we've
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previously identified. At this point we focus on active
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verbs in the description, and the analysis of the active
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verbs will give us the operations that we'll need
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to define for our classes. So, again, underline nouns, and
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those will become the classes in my system. Then,
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objectives. And, those will be the attributes of the classes.
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And, finally, active verbs that will become the operations of my classes. And
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of course, this is a high level view to take this with a
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grain of salt. But we will see that it's a very good pragmatic
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approach to identifying requirements, starting from a
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description of the system to be built.
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