如何创建布尔方法

Question

我正在尝试创建一个名为isAvailable的布尔方法，该方法接受航班上的座位号作为参数，返回一个指示该座位是否可用的布尔值。使用类似于井字游戏程序的代码，该代码将把20这样的座位号转换为二维数组的行和列索引。如果航班上有任何可用座位，则返回true。

    public class Flight {
     /*
     * declare instance variables
     * each flight object that is created will have its own copy of these
     * These are declared as private to ensure that external Java code
     * cannot access them directly and assign any arbitrary values to them.
     */
     String flightNumber;
     int rows;
     int seatsPerRow;
     boolean [][] seat;
     double fare;
     String origin;
     String destination;

     /*
     * The constructor
     * Contains code that initially sets up each flight object when it is
     * first created. Always has the same name as the class.
     */
     public Flight (String flightNumber, int rows, int seatsPerRow, double fare,  String origin, String destination) {
    //call the mutator methods and let them initialize the instance variables
    setflightNumber(flightNumber);
    setRows(rows);
    setSeatsPerRow(seatsPerRow);
    setFare(fare);
    setOrigin(origin);
    setDestination(destination);
    seat = new boolean [rows][seatsPerRow]
    for(int i = rows, int x = seatsPerRow; i>0, x>0; i--, x--){
        seat[i][x] = true;
    }
     }//end of constructor

         /*
         * The accessor methods
     * These report the current values of the Flight object's instance variables
     */
     public String getFlightNumber() {
         return flightNumber;
     }
     public int getRows() {
         return rows;
     }
     public int getSeatsPerRow() {
         return seatPerRow;
     }
     public double getFare() {
         return fare;
     }
     public String getOrigin() {
         return origin;
     }
     public String getDestination() {
         return destination;
     }
     public boolean isAvailable(int userRow, int userSeatPerRow) {
    int row = 0;
    int seatPerRow = 0;
     }
}//end of accessors

Answer 1

这就是您想要的吗？

public boolean isAvailable(int userRow, int userSeatPerRow) {
      return !seat[userRow][userSeatPerRow];
} 

这假设seat[x][y]阵列是真的，如果座位在x排，位置y被占用

如果座位被占用，则seat[userRow][userSeatPerRow]为true。

当!时，我们得到了反转的逻辑，所以true变成了false。

因此，函数返回false是座位被占用，因为那时它不可用。如果座位是空的，情况正好相反。然后函数返回true

要找到第一个可用的座位，你可以这样做：

 for (int row = 0; row < getRows(); row++) {
     for (int column = 0; column < getSeatsPerRow(); column++) {
         if (isAvailable(row, column)) {
             System.out.println("Sear " + row +", " + column + " is emply!!!!!!");
         }
     } 
 }

检查是否有可用座位

public boolean areThereAnyAvailableSeats() {
    for (int row = 0; row < getRows(); row++) {
        for (int column = 0; column < getSeatsPerRow(); column++) {
            if (!seat[userRow][userSeatPerRow]) {
                return true;
            }
        } 
    }
    return false;
} 

Answer 2

您的函数

public boolean isAvailable(int userRow, int userSeatPerRow) {
    int row = 0;
    int seatPerRow = 0;
     }

不返回任何内容。是因为你不知道该放什么，还是忘记了。。。？

大概，您会想要一个将seat设置为false的"book"方法（在seat[][]数组中切换一点）；isAvailable方法需要访问数组并返回值

return seat[userRow][userSeatPerRow].

在您的方法中将row和seatPerRow设置为零，而这些都是传入的参数，这让我感到困惑。