java中将if-else-if语句转换为switch语句
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Converting an if-else-if statement into a switch statement in java
提问by zaynv
I'm having trouble turning this program from an if-else-if statement into a switch statement. Any help would be appreciated.
我无法将此程序从 if-else-if 语句转换为 switch 语句。任何帮助，将不胜感激。
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.");
}
}
}
采纳答案by MeIr
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.");
}
}
}
回答by Idan Arye
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.");
}
回答by arshajii
You probably want something like:
你可能想要这样的东西：
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.");
}
I urge you to read the switch statement tutorial, which should explain how/why this works as it does.
我敦促你阅读switch 语句教程，它应该解释它是如何/为什么这样做的。
回答by santhosh
/* Just change choice to 1
* if you want 2 or 3 or 4
* just change the switch(2 or 3 or 4)
*/
switch(1)
{
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 : You selected 1.
答案：您选择了 1。
