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try it out 9-5
Combine FindAverage, FindMax, and FindMin into one procedure (called
ProcessList) that will display the average, maximum, and minimum values for
the score list all at the same time .

Searching and Sorting Lists

Suppose you have a list of contacts that isn’t in any particular order. If you
wanted to organize the contacts, you might sort them into alphabetical order
based on their names. If you need to know someone’s phone number and
you have their last name, you’ll need to search the list to see if it contains
that person’s contact information. The goal of this section is to introduce
basic programming techniques for searching and sorting lists.

Linear Search

SearchList .sb2 Scratch’s contains block provides an easy way to check whether a list contains
a specific item. If, in addition, we’d like to know the position of the item
being searched for in a list, then we have to perform the search ourselves.
This section will explain one method for searching lists, called a linear
search (or sequential search). The method is easy to understand and imple-
ment, and it works on any list, whether it is sorted or not. However, because
a linear search compares the target value with every element in the list, it
can take a long time if your list is large.
To illustrate, suppose you’re searching for a specific item in a list
named fruit. If the list contains the item you are looking for, you also need
to know the exact position of that item. The SearchList procedure shown in
Figure 9-19 performs a linear search on the fruit list to give us the answers
we seek.

Figure 9-19: The SearchList procedure

226 Chapter 9
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