循环输入,直到控制台输入的内容为Y/y或N/n才结束,输入其他内容则提示错误。
import java.util.Scanner;
public class test {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
boolean isValid = false;
while (!isValid) {
String str = sc.next();
if (str.equalsIgnoreCase("y")) {
System.out.println("YES");
isValid = true;
} else if (str.equalsIgnoreCase("n")) {
System.out.println("NO");
isValid = true;
} else {
System.out.println("Please input \"y\" or \"n\"");
}
}
}
}