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问候。除了一项要求外，我已经完成了一所学校的项目。与遗产有关的家庭作业
的要求是：
注意，SeaCreature类定义了不同方向的四个常数。确保使用它们。尽管您可能会认为它们始终是int类型，但您的代码不应该依赖于分配给这些常量的特定值。
我看不到这个值。分配的常量值是逻辑上的，并且可以方便地使用随机返回方向。如果分配的值是四个非连续的数字，这会使代码真的变得复杂。
下面是在作业中提到的原始SeaCreature类，然后是我的一个使用Random的生物的代码。除了在每个类别中涉及随机移动的NORTH，SOUTH，EAST，WEST分配新值之外，是否有更清晰的方法来返回基本方向而不是0-3的值？
非常感谢您的建议，并请询问是否需要澄清。
import java.util.*;
/**
* Defines the attributes and behaviors common to all SeaCreatures in order to participate
* in the SeaCreature simulation.
*
* Each SeaCreature is represented by a char.
* Each SeaCreature can answer back its char when asked.
* Each SeaCreature can answer its next move, NORTH, SOUTH, EAST, WEST.
*
*/
public abstract class SeaCreature {
private char ch;
/** defined constant to facilitate random movement*/
public static final Random rand = new Random();
/** defined constant to move one unit NORTH */
public static final int NORTH = 0;
/** defined constant to move one unit SOUTH */
public static final int SOUTH = 1;
/** defined constant to move one unit EAST */
public static final int EAST = 2;
/** defined constant to move one unit WEST */
public static final int WEST = 3;
/**
* Construct a SeaCreature object with the given character representation
* @param c the character for this SeaCreature
*/
public SeaCreature (char c){
ch = c;
}
/**
* Answers back the character representation for this SeaCreature
* @return this SeaCreature's initial
*/
public char getChar(){
return ch;
}
/** Answers back the next move for this SeaCreature.
* Must be overridden by subclasses
* @return NORTH, SOUTH, EAST, or WEST
*/
public abstract int getMove();
}
我的海狮类：
/**
* Defines the attributes and behaviors specific to SeaLions in order to participate
* in the SeaCreature simulation.
*
* @author Justin Ashburn
* @version 6/5/2011
*/
public class SeaLion extends SeaCreature {
/** defined char to represent a SeaLion*/
private static final char SEALION = 'L';
/** defined steps before SeaLion cycle repeats*/
private static final int CYCLE_LENGTH = 3;
/** defined steps before SeaLion's first direction*/
private static final int DIRECTION_ONE_LENGTH = 2;
private int directionOne;
private int count;
/**
* Construct a SeaLion object with the given character representation
*/
public SeaLion(){
super(SEALION);
// establishes an initial direction
directionOne = rand.nextInt(4);
count = 0;
}
/** Moves like the 'Knight' chess piece. ie. Picks a random direction, moves 2 times
* in that direction, and then randomly chooses a direction perpendicular to the first
* and moves in that direction once.
*
* @return 0, 1, 2, or 3
*/
public int getMove() {
int direction;
int directionTwo;
// continues with direction one for the appropriate length
if (count < DIRECTION_ONE_LENGTH) {
count ++;
direction = directionOne;
}
// if directionOne was east or west chooses a new north or south direction for last move
else if (count < CYCLE_LENGTH && directionOne > 1) {
directionTwo = rand.nextInt(2);
direction = directionTwo;
// resets count and establishes new direction in next cycle
count = 0;
directionOne = rand.nextInt(4);
}
// if directionOne was north or south chooses a new east or west direction for last move
else {
directionTwo = rand.nextInt(2) + 2;
direction = directionTwo;
// resets count and establishes new direction in next cycle
count = 0;
directionOne = rand.nextInt(4);
}
return direction;
}
}
我不明白这与继承有什么关系，除了'extends'关键字的存在。 – 2011-06-07 04:22:47
SeaLion延伸SeaCreature。这是继承。 – Nik 2011-06-07 04:23:40
我看不到你在代码中使用'const'的地方。是的，你使用的是int值，但不是const。我*认为*这就是要求所要求的。在这种特殊情况下没有太多价值，因为这是一个简单的概念。但是你的下一个项目可能是那些'常量不那么简单 - 也许他们是字符串 - 你怎么做到随机1-4？在这种情况下，你应该很容易编写一个GetRandomDirection（）方法，该方法返回一个INT，并且可以从const中随机选取？ – Prescott 2011-06-07 04:35:15