我可以在这段代码中使用 case 语句而不是 if 语句吗？答案

【问题标题】：Can I use a case statement instead of an if statement in this code?我可以在这段代码中使用 case 语句而不是 if 语句吗？
【发布时间】：2017-01-18 08:09:40
【问题描述】：

如您所见，下面的代码中有很多if 语句。

我可以用 case 语句替换它们吗？

package CBM;

import java.util.Scanner;
import java.util.Random;

public class Board 
{
    public static void main(String args[])
    {
    int minplayers, maxplayers;
    minplayers = 2;
    maxplayers = 8;
    String player_0, player_1;

    System.out.println("Start game? (Y/N)");
    Scanner sc = new Scanner(System.in);
    String yn = sc.next();
    if (yn.equals("Y"))
        System.out.println("Starting");
        else
        {
            if (yn.equals("N"))
                System.out.println("Ending");
        }
    System.out.println("How many people are playing?");
    int players = sc.nextInt();
    if (players >= minplayers && players <= maxplayers)
        System.out.println("There are " + players + " players");
        else
        {
            if (players < minplayers || players > maxplayers)
                System.out.println("2-8 players only.");
                System.out.println("Ending");
        }

    if (players == 2)
        System.out.println("To begin both players must each roll the dice once"
                + " to decide who goes first.");

    else

    if (players == 3)
        System.out.println("To begin all 3 players must each roll the dice once"
                + " to decide who goes first.");
    else

    if (players == 4)
        System.out.println("To begin all 4 players must each roll the dice once"
                + " to decide who goes first.");
    else

    if (players == 5)
        System.out.println("To begin all 5 players must each roll the dice once"
                + " to decide who goes first.");
    else

    if (players == 6)
        System.out.println("To begin all 6 players must each roll the dice once"
                + " to decide who goes first.");
    else

    if (players == 7)
        System.out.println("To begin all 7 players must each roll the dice once"
                + " to decide who goes first.");
    else

    if (players == 8)
        System.out.println("To begin all 8 players must each roll the dice once"
                + " to decide who goes first.");

【问题讨论】：

是的，switch (players) {case 2: ....; break ...

标签： java if-statement switch-statement case

【解决方案1】：

你不需要if 或 switch。只需动态插入玩家数量（第一种情况除外）：

if (players == 2)
    System.out.println("To begin both players must each roll the dice once"
            + " to decide who goes first.");
else
    System.out.println("To begin all " + players + " players must each roll the dice once"
            + " to decide who goes first.");

【讨论】：

【解决方案2】：

您只需要检查players == 2，因为您想打印出both这个词，在所有其他情况下，您只需打印出变量players，因为您已经检查过它是在代码前面的正确范围 (2-8) 中。

if (players == 2)
    System.out.println("To begin both players must each roll the dice once to decide who goes first.");
else
    System.out.println("To begin all " + players + " players must each roll the dice once to decide who goes first.");

如果你想使用 switch 语句，你可以这样做：

switch (players) {
  case 2:
    System.out.println("To begin both players must each roll the dice once to decide who goes first.");
    break;
  default:
    System.out.println("To begin all " + players + " players must each roll the dice once to decide who goes first.");
    break;
}

【讨论】：

感谢您的回复 :)

【解决方案3】：

您应该考虑检查何时players == 2 和何时players > 2 以删除许多不必要的情况。无论如何，如果您想使用 case 语句，它将是：

switch(players)
{
 case 2:
 //your code
 break;
 case 3:
 //your code
 break;
 ...
 }

【讨论】：