Software Engineering for Students A Programming Approach

CHAPTER
12
This chapter explains:
12.1 ● Introduction
Experienced programmers draw on half-remembered memories of software structures
that they have used themselves or seen used in the past. An example of a simple programming
pattern is the design of a program to find the largest number in an array of
numbers. The simplest algorithm uses a variable to record the largest value that has yet
been encountered. The program starts at the beginning of the array and proceeds item
by item, examining each number, updating this variable as necessary:
largest = list[0]
index = 0
while index largest then
largest = list[index]
end if
index = index + 1
end while
Design patterns
■ how to use design patterns during development
■ several major design patterns
■ some valuable anti-patterns.
This is clearly a small piece of program that is easily constructed by any experienced
programmer, but to novice programmers, seeing this is something of a revelation. And
once seen, the programmer never forgets it. Or at least the programmer remembers
the idea of what is needed, rather than the detail. This is a software pattern. Over a
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