java - 查明 for 循环中的数据是否满足特定条件

Question

我想做的是弄清楚如何查看 for 循环中的数据是否满足特定条件。我想使用 if 语句来执行此操作(除非有更好的方法)，但我遇到的麻烦是数据位于 for 循环内，并且代码不希望我使用该循环之外的值环形。这是代码:

    //Create an array called schoolEnrollment of length numberOfStudents         
    Student[] myArray = new Student[numberOfStudents];  


    //Create enough objects of type Student to fill the array above
    for (int i = 0; i < numberOfStudents; i++) {

        //Uses the instance of RandomNames to assign first and last names to each student
            //First names
            String[] firstNames1 = {"John", "Roxanne", "Dean", "Mary", "Shawn", "Sara",
                    "Peter", "Susie", "Jerry", "Juliet"};

            int idx = new Random().nextInt(firstNames1.length);
            String random = (firstNames1[idx]);

            String NextFirstName = random;

            //Last names
            String[] lastNames1 = {"Smith", "Brown", "Baker", "Doe", "Poe", "Allen", 
                    "Black", "Frederick", "Hunter", "Spencer"};

            int idx1 = new Random().nextInt(lastNames1.length);
            String random1 = (lastNames1[idx1]);

            String NextLastName = random1;


        //Randomly assign house locations to each student
        int houseLocation = (int) (0 + (Math.random() * (3 - 0)));
        //Randomly assign distance from school to each student
        int distanceFromSchool = (int) (0 + (Math.random() * (30 - 0)));;
        myArray[i] = new Student(NextFirstName, NextLastName, houseLocation, distanceFromSchool);

    }

    for (int i = 0; i < numberOfStudents; i++) {
        // display toString for each object
        System.out.println(myArray[i].toString());
    }

    //Create 4 other arrays of length numberOfStudents of type Student with the names
    //ridersOfNorthBus, ridersOfWestBus, ridersOfSouthBus, and ridersOfEastBus
    Student[] ridersOfNorthBus = new Student[numberOfStudents];

    Student[] ridersOfWestBus = new Student[numberOfStudents];

    Student[] ridersOfSouthBus = new Student[numberOfStudents];

    Student[] ridersOfEastBus = new Student[numberOfStudents];

所以，我想做的是获取 for 循环随机给出的 houseLocation(东、南、北或西)来看看谁会乘坐哪辆公共(public)汽车。简单地尝试使用 houseLocation 变量是行不通的，因为程序无法识别 for 循环之外的变量。此外，创建该变量的另一个随机实例是行不通的，因为它可能不会得出相同的值。我也无法将代码放入 for 循环中，因为这样我的数组就会多次打印出来，这不是我想要的。有什么办法可以做到这一点吗？谢谢。

另外，不确定是否需要它，但这是包含 houseLocation 方法的类:

public class Student {

//Create private instance variables with setters and getters
private String firstName;
private String lastName;
private int houseLocation = 0;
private int distanceFromSchool = 0;


//Set values for private instance variable house location
public void north() {
    int North = 0;
    if (houseLocation == North)
        North = houseLocation;

}
public void west() {
    int West = 1;
    if (houseLocation == West)
        West = houseLocation;
}
public void south() {
    int South = 2;
    if (houseLocation == South)
        South = houseLocation;
}
public void east() {
    int East = 3;
    if (houseLocation == East)
        East = houseLocation;
}

Answer 1

您不应该使用 houseLocation 变量进行比较，因为它的范围仅在 for 循环内。相反，您应该为 Student 类提供一个 getter 方法来获取特定实例的 houseLocation。例如。

myArray[i].getHouseLocation(); //something like this to access the houseLocation for each element (Student) of the array...

您已经在构造函数中为每个学生设置了房屋位置，只需创建或(使用您已有的 getter)来访问数据。

Student类中的Getter方法:

public int getHouseLocation()
{
   return this.houseLocation;
}