Java中是否有命令使程序返回循环的开头

Question

我正在尝试用Java进行打字冒险类游戏，但是我至少需要一个与标题中的命令相似的命令，这是代码

import java.util.Scanner;

public class MyFirstGameInJava {

public static void main(String[] args) {

System.out.println("Greetings, Enter your name and you may start your quest!");
Scanner Username = new Scanner(System.in);
String name = Username.nextLine();
System.out.println("Greetings " + name );
System.out.println("Welcome to an Unnamed Typing Advanture");
System.out.println("You find yourself on an island with very few trees, you can either hit a tree, or walk along");

String sc = Username.nextLine();

switch(sc){

case "Hit tree":
System.out.println("A coconut falls from the tree");
System.out.println("You can either eat the coconut or throw it");
break;
case "Walk":
System.out.println("You walk for a mile and find a village");
System.out.println("The village appears empty, you can either scream to see if anybody is there, or you can keep walking");
break;
default :
System.out.println("Nothing happens...");
}   

String sc1 = Username.nextLine();


switch(sc1){

case "Eat coconut":
System.out.println("You ate the coconut and got poisoned");
System.out.println("You died...");
break;
case "Throw coconut":
System.out.println("By throwing the coconut, you awaken a tiger and he eats you");
System.out.println("You are dead");
break;
case "Scream":
System.out.println("As soon as you scream, a man shoots you down from a window from one of the houses");
System.out.println("You died...");
break;
case "Walk":
System.out.println("You walked through the village, and you find a boat and leave the island");
System.out.println("You win! Updates coming soon!");
break;
default:
System.out.print("Nothing happend");



}

}

}

每当用户键入除要求之外的其他内容时，就会发生默认情况，但是我需要它返回到循环的开始，因此用户可以键入其他情况之一。

Answer 1

您可以使用continue语句继续进行下一个迭代。

就是说，我没有在示例代码中看到循环。 您可以使用for ， while或do/while循环。 do / while循环至少执行一次-这通常是在询问用户问题时要执行的操作。

本Java分支语句教程提供了for循环中的continue语句示例。

   for (int i = 0; i < max; i++) {
        // interested only in p's
        if (searchMe.charAt(i) != 'p')
            continue;

        // process p's
        numPs++;
    }

Answer 2

使用continue; 以无条件循环为例

while(true){/* your code*/}

Answer 3

您的问题做出了错误的假设。 switch()语句不是循环。 这是一堆if / else-if语句的简写：

if(sc1.equals("Eat coconut")) {
    System.out.println("You ate the coconut and got poisoned");
    System.out.println("You died...");
}
else if(sc1.equals("Throw coconut")) {
//and so on

要执行所需的操作，您将需要一个实际的while()或for()循环。 （这些链接将带您进入解释这两种构造的Java教程。）

Answer 4

我的CS课也遇到了同样的问题：这就是我所做的。 首先，您需要使用循环。 我使用了一个“ while”循环。

因此，假设您在对话中的某个时刻，有人要问别人（例如武术大师问玩家），而答案选择是“ y”或“ n”。 但是玩家输入“ m”。 这将产生一个错误。 要解决此问题，您需要进行一些操作（循环），以继续检查用户是否键入了有效的响应，并相应地继续执行程序。 现在的代码...

//Ask if they want to see the rules.    
System.out.println("Welcome Player One");  
System.out.println("Would you like to read the rules of the gem?");  
System.out.println("[y]Yes, please / [n]I know the rules."); //So you made it clear that the choices are 'y' or 'n' (yes or no).

//Decide if they hit yes or no.  
char Response; //Variable to hold user response.  
Scanner Console = new Scanner(System.in); //I don't know why, exactly, but you need this.  
Response = Console.next().charAt(0); //Set response to the user input. A input field will appear.  
while(true){  //Making the parameter 'true' makes the flow of the loop depend on the parameters in the if statements (I think).  
  if(Response == 'y' || Response == 'Y'){  
   System.out.println("Here are the rules:");  
   break; //break will make the flow exit the while loop (so you can continue adding the rest of your code).  
  }  
  else if(Response == 'n' || Response == 'N'){  
   System.out.println("Then let us continue:");  
   break;  
  }  
  else{  
   System.out.println("Would you like to read the rules of the gem?"  
   System.out.println("You have to enter (y)yes or (n)no...");  
   Response = Console.next().charAt(0); //Just like before, input field will  appear to give them the chance to change their response to a valid one.  
   continue; //This has to be 'continue' so that the loop will continue to "check" for the value that needs to be input by the user.  
  }  
}

希望这会有所帮助，欢呼。

Answer 5

不太详细，更直接。 我已经解释了简单的答案。

for(int i = 0; i <= 10; i++){
        if(i == 4){
            continue;
        }
        //Should skip 4 and print out 1,2,3,5,6,7,8,9,10
        System.out.println(i);
    }