java - 为什么 course[] 对象不能跟随指向 double 的指针？

Question

对于我的 java 编程类(class)，我正在尝试编写一个程序来判断类是否冲突。到目前为止，我有一个名为 Course 的对象。 public void init将初始化上述所有成员的类(class)，然后 public boolean conflict(Scanner scan)这是我们发现与日程发生冲突的地方。和public String toString返回类(class)的名称和时间。我的问题是，由于我在附图中指出的编译错误，考虑到 othercourse 是 Course[] (类(class)数组)指针，我将如何设置 othercourse 来比较时间并获取结束时间？

到目前为止，我已经尝试过othercourse[i].end_time = time + length / class_period * per + length % class_period;这会返回一个无法找到符号的编译错误。

if 语句也是如此，if (othercourse[i].length course.time && course.time < othercourse[i].length)

我想知道如何设置 othercourse.time和othercourse.length正确遵循指示。预先感谢您。

import java.util.*;

public class Course {

  public static final int class_period = 60;
  public static final double per = 100;

  public String name; // ie: CS142, CS141, ENG 101
  public String instructor; // ie: John Mill, Bob the Fish
  public String room; // ie: 127A, 18-218, the bathroom
  public int time; // in military notation.  ie: 1030, 1600 etc
  public int length; // length in minutes.  50 means the course
  // lasts 50 minutes. 
  public double end_time;

  // name: init
  // desc: reads in entries for the members from the user
  // params: Scanner scan
  // return: void  
  // 1) for each member do steps 2-3.    
  // 2)  prompt the user to enter a value
  // 3)  read in that value and store in the member

  public void init(Scanner scan) {

      //Steps 1-3
      System.out.print("Please enter in a course name: ");
      name = scan.next();
      System.out.print("Please enter in the name of an instructor: ");
      instructor = scan.next();
      System.out.print("Please enter in the room number: ");
      room = scan.next();
      System.out.print("Please enter in the start time: ");
      time = scan.nextInt();
      System.out.print("Please enter in the length of the course: ");
      length = scan.nextInt();
    }
    // name: conflict
    // desc: returns true if this course conflicts with the parameter
    // params: Course othercourse
    // return: boolean - true if the courses conflict
    // 1) if this course and othercourse start at the same time, return true
    // 2) calculate the end time of this course ( start time + length/60*100 + 
    //      length % 60 )
    // 3) calculate the end of the othercourse
    // 4) if this course starts after other course, and starts before 
    //  the other course ends, return true
    // 5) if the other course starts after this course, and starts before
    //  this course ends, return true
    // 6) return false

  public boolean conflict(Course[] othercourse, Course course) {

    //Step 1
    if (this.time == othercourse.time)
      return true;

    //Step 2
    course.end_time = time + length / class_period * per + length % class_period;

    //Step 3
    othercourse.end_time = time + length / class_period * per + length % class_period;

    //Step 4
    if (this.time > othercourse.length && course.length < othercourse.time)
      return true;

    //Step 5
    if (othercourse.length  course.time && course.time < othercourse.length)
      return true;

    //Step 6
    return false;
  }

  // name: print
  // desc: returns a string that represents some basic info about the course 
  // params: none
  // return: String
  // 1) return a string of the format "Course " + name + " with start time " + 
  //    time

  public String toString() {
    return name + time;
  }

}

Answer 1

所以第一件事是第一件事。您的方法(甚至根据评论)应该只采用一个参数，即要进行比较的类(class)。您已经拥有全局范围内的当前类(class)信息。所以你的方法签名如下:

public boolean conflict(Course othercourse) {

对于第 3 步，您需要使用其他类(class)的信息。

//Step 3
othercourse.end_time = othercourse.time + othercourse.length / othercourse.class_period 
                * othercourse.per + othercourse.length % othercourse.class_period;

现在，当您调用该方法时，它是

othercourse[i].conflict(course);

此外，您在任何地方引用course将其替换为 this或者简单地删除它(即 course.time 变为 this.time 或 time )。