Question

我正在尝试为我的java类编写Java代码，并且在运行代码时收到以下错误消息：

"Type mismatch: cannot convert from String to int;"

这是作业：

"Write a program that reads in a single digit number from the keyboard into an
integer variable. Your program will then print the number spelled out. If the user
types in a number that is more than one digit, your program must print an error
message. If the user types in a negative number, your program should print the word
"negative" before the digit spelled out."

这是我到目前为止所做的：

import java.util.Scanner;

public class ReadsNumber{

    public static void main(String[] args){

        String[] a = new String[10];

         a[0] = "Zero";
         a[1] = "One";
         a[2] = "Two";
         a[3] = "Three";
         a[4] = "Four";
         a[5] = "Five";
         a[6] = "Six";
         a[7] = "Seven";
         a[8] = "Eight";
         a[9] = "Nine";

         Scanner inputStream = new Scanner(System.in);  
         int integer;

         while(true){
             System.out.println("Input an integer: ");
             integer = inputStream.next();
             if (integer < 0)
                 System.out.println("negative");
             else if (integer > 9)
                 System.out.println("error");
             else 
                 System.out.println(a[integer]);
         }

     }
}

Answer 1

next method returns a String，它无法自动转换为int。请改为呼叫nextInt。

integer = inputStream.nextInt();

您可能还想致电hasNextInt()以确定Scanner上的下一个实际上是否为整数。

Answer 2

您需要~~先解析整数~~使用Scanner#nextInt()：

integer = inputStream.nextInt();

然后将从输入中读取一系列字符，并将它们转换为整数。如果输入无效（不是整数或太大），则抛出异常并终止程序。

Answer 3

亲爱的朋友，您使用过扫描仪将输入作为整数获取，但您已使用$( document ).tooltip();

但由于您的输入是整数，因此您必须使用inputstream.next(); 因为next（）用于获取字符串而nextInt（）用于获取Integer。

类型不匹配：无法从String转换为int

3 个答案: