如何调用if语句中相同类中的不同方法

Question

我试图从布尔方法中的if语句中的step（）方法调用方向，但它一直说它找不到可变方向。任何人都可以帮我弄清楚如何正确地做到这一点？

public class SelfAvoidingRandomWalk 
{ 
    private char[][] board ; 
    private char symbol ; 
    private int lengthOfWalk, currRow, currColumn ; 

    public SelfAvoidingRandomWalk(int numRows, int numColumns, 
           int startRow, int startColumn) 
    { 
     board = new char[numRows][numColumns] ; 
     lengthOfWalk = 0 ; 
     symbol = '$' ; 
     board[startRow][startColumn] = symbol ; 
     currRow = startRow ; 
     currColumn = startColumn ; 
    } 

    private final static int NORTH = 8 ; 
    private final static int SOUTH = 2 ; 
    private final static int WEST = 4 ; 
    private final static int EAST = 6 ; 

    public void step(int direction) 
    { 
     if (direction == NORTH) 
     { 
      if (currRow == 0) 
      { 
       currRow = board.length ; 
      } 
      currRow-- ; 
      symbol = 'N' ; 
     } 
     else if (direction == SOUTH) 
     { 
      currRow = (currRow + 1) % board.length ; 
      symbol = 'S' ; 
     } 
     else if (direction == EAST) 
     { 
      currColumn = (currColumn + 1) % board[0].length ; 
      symbol = 'E' ; 
     } 
     else if (direction == WEST) 
     { 
      if (currColumn == 0) 
      { 
       currColumn = board[0].length ; 
      } 
      currColumn-- ; 
      symbol = 'W' ; 
     } 
     board[currRow][currColumn] = symbol ; 
    } 

    public boolean canTakeStep() 
    { 
     boolean stepOk = true ; 

     if (board[currRow + 1][currColumn] == symbol) 
     { 
      if (step(2) == SOUTH) 
      { 
       stepOk = false ; 
      } 
     } 

     if (board[currRow - 1][currColumn] == symbol) 
     { 
      if (step(8) == NORTH) 
      { 
       stepOk = false ; 
      } 
     } 

     if (board[currRow][currColumn + 1] == symbol) 
     { 
      if (step(6) == EAST) 
      { 
       stepOk = false ; 
      } 
     } 

     if (board[currRow][currColumn - 1] == symbol) 
     { 
      if (step(4) == WEST) 
      { 
       stepOk = false ; 
      } 
     } 

     return stepOk ; 
    } 

    public int length() 
    {   
     if (canTakeStep() == true) 
     { 
      lengthOfWalk++ ; 
     } 
     else 
     { 
      System.out.println("The length of your walk was: " + lengthOfWalk) ; 
     } 

     return lengthOfWalk ; 
    } 

    public void print() 
    { 
     printTopBottom() ; 

     for (int r = 0; r < board.length; r++) 
     { 
      System.out.print("|") ; 

      for (int c = 0; c < board[r].length; c++) 
      { 
       if (symbol == '$' || symbol == 'N' || symbol == 'S' || symbol == 'W' || symbol == 'E') 
       { 
        if (board[r][c] != symbol) 
        { 
         System.out.print(" ") ; 
        } 

        else 
        { 
         System.out.print(symbol) ; 
        } 
       } 
      } 

      System.out.println("|") ; 
     } 

     printTopBottom() ; 
    } 

    private void printTopBottom() 
    { 
     System.out.print("+") ; 

     for (int c = 0; c < board[0].length; c++) 
     { 
      System.out.print("-") ; 
     } 

     System.out.println("+") ; 
    } 
} 

这里是驱动程序类的主要方法：

import java.util.Scanner ; 

public class Lab2 
{ 
    public static void main(String args[]) 
    { 
     Scanner input = new Scanner(System.in) ; 

     System.out.print("Enter number of rows: ") ; 
     int numRows = input.nextInt() ; 
     System.out.print("Enter number of columns: ") ; 
     int numColumns = input.nextInt() ; 
     System.out.print("Enter start row: ") ; 
     int startRow = input.nextInt() ; 
     System.out.print("Enter start column: ") ; 
     int startColumn = input.nextInt() ; 

     System.out.println() ; 

     SelfAvoidingRandomWalk selfAvoidingRandomWalk = new SelfAvoidingRandomWalk(numRows, numColumns, 
      startRow, startColumn) ; 

     selfAvoidingRandomWalk.print() ; 

     while (selfAvoidingRandomWalk.canTakeStep() == true) 
     { 
      System.out.print("Enter the direction you'd like to go: ") ; 
      int theMove = input.nextInt() ; 

      selfAvoidingRandomWalk.step(theMove) ; 
      selfAvoidingRandomWalk.print() ; 
     } 

     selfAvoidingRandomWalk.length() ; 
    } 
} 

Answer 1

你的步法接收INT方向参数和你canTakeStep方法没有。只需按照与步骤方法相同的方式传递变量即可：

public boolean canTakeStep(int direction) 
{ 

}