Introduction to Objects - Advanced Topics in Java: Core Concepts in Data Structures - page 62

We need to store the names of the seven candidates and the score obtained by each. We could use a String array
for the names and an int array for the scores. But what if we needed to store many more attributes of a candidate? For
each attribute, we would need to add another array of the appropriate type. To cater for this possibility and to make
our program more flexible, we will create a class Person and use an array of Person .
What will this Person class look like? For our problem, it will have two instance fields, name and numVotes , say.
We define it as follows:
class Person {
String name;
int numVotes;
Person(String s, int n) {
name = s;
numVotes = n;
}
} //end class Person
To cater for seven candidates, we set the symbolic constant MaxCandidates to 7 and declare the Person array
candidate as follows:
Person[] candidate = new Person[MaxCandidates+1];
We will use candidate[h] to store information for candidate h , h = 1 , 7 ; we will not use candidate[0] . This will
enable us to process the votes more naturally than if we had used candidate[0] . For example, if there is a vote for
candidate 4, we want to increment the vote count for candidate[4] . If we had used candidate[0] to store information
for the first candidate, we would have had to increment the count for candidate[3] , given a vote of 4. This can be
misleading and disconcerting.
Suppose in is declared as follows:
Scanner in = new Scanner(new FileReader("votes.txt"));
We will read the names and set the scores to 0 with the following code:
for (int h = 1; h <= MaxCandidates; h++)
candidate[h] = new Person(in.nextLine(), 0);
When this code is executed, we can picture candidate as shown in Figure 2-11 . Remember, we are not using
candidate[0] .