使用Java类的随机值并在Main上打印它

Question

我需要为变量agentPosX和agentPosY使用随机值，并且我需要打印它们以查看它们获得的值。

代码很长，但是我需要帮助的行是52、53和322。

我用了static，但我认为它是不对的。

感谢

import java.util.*;
import java.io.*;

public class WumpusWorld {
public static final int PIT_FLAG        = 1;
public static final int WUMPUS_FLAG     = 2;
public static final int GOLD_FLAG       = 4;
public static final int BREEZE_FLAG     = 8;
public static final int STENCH_FLAG     = 16;
public static final int GLITTER_FLAG    = 32;
public static final int BUMP_FLAG       = 64;
public static final int SCREAM_FLAG     = 128;
private static final int FACING_NORT    = 1;
private static final int FACING_EAST    = 2;
private static final int FACING_WEST    = 3;
private static final int FACING_SOUTH   = 4;
/*
 * Actions
 */
public static final int GO_FORWARD      = 1;
public static final int TURN_LEFT       = 2;
public static final int TURN_RIGHT      = 3;
public static final int GRAB            = 4;
public static final int SHOOT           = 5;
public static final int CLIMB           = 6;
public static final String STR_GO_FORWARD   = "Avanzar";
public static final String STR_TURN_LEFT    = "Izquierda";
public static final String STR_TURN_RIGHT   = "Derecha";
public static final String STR_GRAB         = "Agarrar";
public static final String STR_SHOOT        = "Disparar";
public static final String STR_CLIMB        = "Escalar";
//matriz random
/*
 * Perceptions
 */
private int     perceptions = 0;
public  double  actionCost  = 1.0;
public  double  outWithGold = 1000.0;
public  double  killCost    = 10000.0;
public  int     worldDimensionX;
public  int     worldDimensionY;
public  double  pitProbability;
public static  int  agentPosX   = (int)Math.random()*10;
public  static int  agentPosY   = (int)Math.random()*10;
private int     agentDir    = FACING_EAST;
private boolean agentSafe   = true;
private double  agentScore  = 0.0;
private boolean agentArrow  = true;
private boolean agentGold   = false;
private boolean agentOut    = false;
private int world[];
PrintStream out = System.out;
Scanner reader;

public static void main(String args[]) {
//WumpusWorld prin = new WumpusWorld(worldDimensionX,worldDimensionY, pitProbability, actionCost, outWithGold, killCost);
    int n = 100;
    if ( args.length == 1 ) {
        try {
            n = Integer.parseInt(args[0]);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    System.out.println("SIMULATION_STARTED");
    System.out.println("gato: " + agentPosX + " gatoY: " + agentPosY);

    for (int i = 0; i < n; i++) {
        WumpusWorld world = new WumpusWorld(10, 
                            10, 
                            0.15,
                            1, 
                            1000, 
                            1000);
        System.out.println("EPISODE_STARTED");
        while ( world.isAgentOk() & !world.isAgentOut() ) {
            System.out.println( world.getPerceptions() );
            world.readAction();
        }
        System.out.println("EPISODE_ENDED, AGENT_SCORE=" + world.agentScore);
        String line = world.readLine();
        if ( !"START_SIMULATION_REQUEST".equals(line) ) break;
    }
}
}

Answer 1

这一行基本上就是你代码中的内容。

    System.out.println( (int)Math.random()*10 );   // prints zero

上面的代码将始终打印零。为什么?因为您正在四舍五入的小数值是<1的整数次方。它总是零。要更清楚地了解这一点，请考虑以下示例:

    double v = Math.random();
    System.out.println( v );             // prints a decimal < 1
    System.out.println( (int) (v*10) );  // prints a value between 1 and 9
    System.out.println( (int) v*10 );    // prints 0

Answer 2

像这样转换Math.random()的结果太早了，您希望先进行乘法运算-

public static int agentPosX = (int) (Math.random()*10);
public static int agentPosY = (int) (Math.random()*10);

我建议你使用Random，

private static Random rand = new Random();
public static int agentPosX = rand.nextInt(10) + 1;
public static int agentPosY = rand.nextInt(10) + 1;