在java编程中使用扫描器类以及使用数字的switch case语句
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in java programming use a scanner class along with switch case statement using numbers
提问by user2744779
Can anybody tell me how to use "switch-case" for numbers along with scanner class, so that a number read from the keyboard should compare with switch cases given and final output should be printed?
谁能告诉我如何将“开关盒”用于数字和扫描仪类，以便从键盘读取的数字应与给定的开关盒进行比较并打印最终输出？
import java.util.Scanner;
public class Switchcase{
public static void main(String[] args) {
int age;
Scanner bhavya = new Scanner(System.in);
System.out.println("enter your age:");
age = bhavya.nextInt();
switch (age) {
case 1:
System.out.println("you can crawl");
break;
case 2:
System.out.println("you can talk");
break;
case 3:
System.out.println("you can get in trouble");
break;
default:
System.out.println("i dnt know how old you are");
break;
}
}
回答by Stephen C
Your program works ... apart from the fact that you are not dealing with the case where the user enters something that is not a valid integer.
您的程序可以正常工作......除了您没有处理用户输入的内容不是有效整数的情况之外。
You need to either use Scanner.hasNextInt()to test if the next token is an integer or catch and diagnose the exception that is thrown by Scanner.nextInt()when it can't read an int.
您需要使用Scanner.hasNextInt()来测试下一个标记是否为整数，或者捕获并诊断Scanner.nextInt()无法读取int.
