在java中將if-else-if語句轉換爲switch語句

Question

我無法將此程序從if-else-if語句轉換爲switch語句。任何幫助，將不勝感激。

import java.util.Scanner; 

public class ifToSwitchConversion { 


    public static void main(String [] args) { 

     // Declare a Scanner and a choice variable 
     Scanner stdin = new Scanner(System.in); 
     int choice = 0; 

     System.out.println("Please enter your choice (1-4): "); 
     choice = stdin.nextInt(); 

     if(choice == 1) 
     { 
      System.out.println("You selected 1."); 
     } 
     else if(choice == 2 || choice == 3) 
     { 
      System.out.println("You selected 2 or 3."); 
     } 
     else if(choice == 4) 
     { 
      System.out.println("You selected 4."); 
     } 
     else 
     { 
      System.out.println("Please enter a choice between 1-4."); 
     } 

    } 


} 

Answer 1

import java.util.Scanner; 

public class ifToSwitchConversion { 

public static void main(String [] args) { 

    // Declare a Scanner and a choice variable 
    Scanner stdin = new Scanner(System.in); 
    int choice = 0; 

    System.out.println("Please enter your choice (1-4): "); 
    choice = stdin.nextInt(); 


    switch(choice) { 
     case 1: 
      System.out.println("You selected 1."); 
      break; 
     case 2: 
     case 3: 
      System.out.println("You selected 2 or 3."); 
      break; 
     case 4: 
      System.out.println("You selected 4."); 
      break; 
     default: 
      System.out.println("Please enter a choice between 1-4."); 
    } 

    } 

} 

Answer 2

switch(choice) 
{ 
    case 1: 
     System.out.println("You selected 1."); 
     break; 
    case 2: 
    case 3: 
     System.out.println("You selected 2 or 3."); 
     break; 
    case 4: 
     System.out.println("You selected 4."); 
     break; 
    default: 
     System.out.println("Please enter a choice between 1-4."); 
} 

Answer 3

你可能想喜歡的事：

switch (choice) { 
    case 1: 
     System.out.println("You selected 1."); 
     break; 
    case 2: 
    case 3: // fall through 
     System.out.println("You selected 2 or 3."); 
     break; 
    case 4: 
     System.out.println("You selected 4."); 
     break; 
    default: 
     System.out.println("Please enter a choice between 1-4."); 
} 

我強烈建議你閱讀switch statement tutorial，這應解釋如何/爲什麼這個工程，因爲它確實。