java - 只是另一个新手 Java 编码器请求批准

Question

所以...我最近正在学习一些 Java，如果您愿意，我希望您能帮助我完成我的第一个程序。这是我的程序代码，它显示牌组中的随机卡片。

我的问题如下:有没有更聪明的方法让这个程序运行？

/*
 * File: RandomCard.java
 * ----------------
 * This program display random card from the deck with it's own rank
 * (Ace, 2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Quenn, King) and suit (Clubs,
 * Diamonds, Hearts, Spades).
 */

import acm.program.*;
import acm.util.*;

public class RandomCard extends ConsoleProgram {
    /* Run the program */
    public void run() {
        println("This program displays a random card from the deck.");
        println("You random card is " + getRandomRank() + " "
                + getRandomSuit() + ".");       
    }

    /* Get random rank for the card. */
    private String getRandomRank() {
        int rank = rgen.nextInt(1, 13);
        switch (rank) {
            case 1: return "Ace";
            case 2: return "2";
            case 3: return "3";
            case 4: return "4";
            case 5: return "5";
            case 6: return "6";
            case 7: return "7";
            case 8: return "8";
            case 9: return "9";
            case 10: return "10";
            case 11: return "Jack";
            case 12: return "Queen";
            case 13: return "King";
            default: return null;
        }
    }

    /* Create random suit from within Clubs, Diamonds, Hearts and Spades. */
    private String getRandomSuit() {
        int suit = rgen.nextInt(0, 3);
        switch (suit) {
            case 0: return "Clubs";
            case 1: return "Diamonds";
            case 2: return "Hearts";
            case 3: return "Spades";
            default: return null;
        }
    }

    /* Create an instance variable for the random number generator */
    private RandomGenerator rgen = new RandomGenerator();
}

Answer 1

一个小的改进:任何时候你有这样的 switch 语句:

 switch (rank) {
        case 1: return "Ace";
        case 2: return "2";
        case 3: return "3";
        case 4: return "4";
        case 5: return "5";
        case 6: return "6";
        case 7: return "7";
        case 8: return "8";
        case 9: return "9";
        case 10: return "10";
        case 11: return "Jack";
        case 12: return "Queen";
        case 13: return "King";
        default: return null;
    }

您可以改为声明一个数组:

String[] ranks = { "Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", 
                   "Jack", "Queen", "King" };

然后:

if (rank < 1 || rank > 13) return null;
return ranks[rank - 1]; // arrays are zero-based