java - 为什么我的代码在输入句子后找不到句点？

Question

为什么我的代码在输入句子后找不到句点？用户应该写一个句子，然后在末尾加一个句号。当进入该时间段时，程序应该结束。帮忙？

import java.io.*;
class Sentence



{
public static void main(String[] args) throws IOException
{
InputStreamReader inStream = new InputStreamReader (System.in);
BufferedReader mVHS = new BufferedReader (inStream);

String inData; //Store the input data in a String    
int result;//Assign the result to the int data type
String sentence, string2; //Store the names in the String type



//Enter a sentance
System.out.println("Type a sentence but make sure it ends with a period:");
Sting userInput = mVHS.readLine();
sentence = userInput;


while(sentence.length()){
    { 

   if(sentence.equals("."))
        System.out.println("Thank you come again.");
   else
    System.out.println("You must put a period to end the program");
    System.out.println("Type a period:");
    userInput = mVHS.readLine();
    sentence = userInput;
}
}
}
}

Answer 1

while(sentence.length()){
    { 

   if(sentence.equals("."))

while 语句中包含无效表达式。并且:如果您只输入了 ，sentence.equals(".") 只会返回 true。

你可以检查:if period.endsWith(".");