Question

我在测试arrayOutOfBounds异常时遇到了麻烦。在下面的代码中，我的if ... else语句应该阻止骑士离开我的棋盘，但是我仍然得到例外。有没有人在这看到我的错误？任何帮助表示赞赏！

public int[][] firstMoveChoice() {
int knight = 0;    
x += 1;
y += 2;

if (x > board.length) { // this tests to make sure the knight does not move off the row
    System.out.println("Cannot move off board on x axis");
    x -= 1;
}
else if (y > board.length) { // this tests to make sure the knight does not move off the column
    System.out.println("Cannot move off board on y axis");
    y -= 2;
}
else { // this moves the knight when the above statements are false
    board[x][y] = ++knight;
    System.out.println("This executed");
}

for(int[] row : board) {
    printRow(row);
}
}

这是最后一块印刷的板子：

This executed
1  0  0  0  0  0  0  0  
0  0  2  0  0  0  0  0  
0  0  0  0  3  0  0  0  
0  0  0  0  0  0  4  0  
0  0  0  0  0  0  0  0  
0  0  0  0  0  0  0  0  
0  0  0  0  0  0  0  0  
0  0  0  0  0  0  0  0  

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 8
at knightstour.Moves.firstMoveChoice(Moves.java:53)
at knightstour.KnightsTour.main(KnightsTour.java:24)
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

这是我的ChessBoard课程：

public class ChessBoard {

int[][] board;

public ChessBoard() {
    this.board = new int[8][8];
}
}

这是我的printRow方法：

public static void printRow(int[] row) {
    for (int i : row) {
        System.out.print(i);
        System.out.print("  ");
    }
    System.out.println();
}

这是我的主要方法。当它调用起始位置时，它所做的就是将board [0] [0]分配给1.尽管你想要实际代码，请告诉我。

public static void main(String[] args) {

    MoveKnight myKnight = new MoveKnight();
    myKnight.startingLocation();
    myKnight.firstMoveChoice();
    myKnight.firstMoveChoice();
    myKnight.firstMoveChoice();
    myKnight.firstMoveChoice(); // this moves the knight off the board
}

Answer 1

您的if条件必须为'＆gt; ='。尝试：

if (x >= board.length) { // This tests to make sure the knight does not move off the row
    System.out.println("Cannot move off board on x axis");
    x -= 1;
}
else if (y >= board.length) { // This tests to make sure the knight does not move off the column
    System.out.println("Cannot move off board on y axis");
    y -= 2;
}

Answer 2

我猜你从0中枚举行/列，而“length”返回数组的真实长度，所以测试表格

if x > board.length

不正确，因为x中只有{0,1,2,3,4,5,6,7}应该是正确的，在您的情况下，8也不会大于8。将这些条件更改为

if x >= board.length

同样适用于y

ArrayOutOfBounds测试代码不起作用

2 个答案: