检查字符中的下一个字母何时在句点之后

Question

所以我正在编写一个练习程序，但我有点卡住了。我想检查char[]数组中的第一个字符是否是字母，我尝试过isLetter，但显然在char中无法做到这一点。

例句："/我叫克里斯"请注意开头的："/"。

我想把它做成第一个字母大写。所以它将是

固定的例句："/我叫克里斯"

我的代码很可能会非常混乱和过度编码，但我还没有到可以缩短它的地步，我还没有那么高级。就像我说的，很可能会很混乱。

这是代码：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.Scanner;
import java.util.StringTokenizer;

public class FileOrUserSentenceHandler 
{
Scanner keyboard = new Scanner(System.in);
String userChoice, fileName;
char period = '.';
String s;
String userSentence;


public String getUserChoice()
{
    System.out.println("Would you like the program to read from a file or a sentence from you? Type 'File' for it to read an already-created file, Type 'me' for it to read a sentence from you.");
    userChoice = keyboard.nextLine();
    return userChoice;
}
public void decideChoice() throws Exception
{
    if(userChoice.equalsIgnoreCase("file"))
    {
        pickedFile();
    }
    else if(userChoice.equalsIgnoreCase("me"))
    {
        pickedMe();
    }
    else
    {
        getUserChoice();
        decideChoice();
    }
}
public void pickedFile() throws Exception
{
    //create file object
    File outFile = new File("CreatedFile.txt");
    BufferedWriter outBWriter = new BufferedWriter(new FileWriter(outFile));
    outBWriter.write("you picked the file option. why not pick the 'me' option?");
    //close the file
    outBWriter.close();
    System.out.println("File was created, Data was written to file.");

    try
    {
        File inFile = new File("CreatedFile.txt");
        BufferedReader inBReader =  new BufferedReader(new FileReader(inFile));
        do
        {
            s = inBReader.readLine();
            if(s == null)
            {
                break;
            }
            System.out.println(s);
            System.out.println("Fixing the sentence from the file...");
            Thread.sleep(3000);
            char[] charArray = s.toCharArray();

            for(int i = 0; i < charArray.length; i++)
            {
                if(i == 0)
                {
                    charArray[i] = Character.toUpperCase(charArray[i]);
                }
                if(charArray[i] == '.')
                {
                    charArray[i + 2] = Character.toUpperCase(charArray[i + 2]);
                }
            }
            System.out.println(charArray);
        }while(s != null);
    }
    catch(Exception e)
    {
        System.out.println("Error. Closing program...");
        System.exit(0);
    }

}
public void pickedMe()
{
    System.out.println("You picked the 'me' option. Please enter a sentence below:");
    userSentence = keyboard.nextLine();
    StringTokenizer userSentenceEdited = new StringTokenizer(userSentence, " "); //creates a tokenized String of userSentence, checks the spaces
    StringBuffer sb = new StringBuffer();
    while(userSentenceEdited.hasMoreElements())
    {
        sb.append(userSentenceEdited.nextElement()).append(" ");
    }
    userSentence = sb.toString();
    //System.out.println(userSentence); // printed out to check if it was working properly
    outerloop : if((userSentence.charAt(userSentence.length() - 1) != '.'))
    {
            if(userSentence.charAt(userSentence.length() - 1) == ' ')
            {
                userSentence = userSentence.trim();
            }
            if(userSentence.charAt(userSentence.length() - 1) == '.')
            {
                //System.out.println("hello");
                break outerloop;
            }
        userSentence += '.';
    }
    //System.out.println(sb.toString().trim());

    char[] userCharArray = userSentence.toCharArray(); //converts the userSentence to a char[] array
    for(int i = 0; i < userCharArray.length; i++)
    {
        if(i == 0) //checks if it's at the beginning of the array, if so, capitalizes it.
        {
            userCharArray[i] = Character.toUpperCase(userCharArray[i]);
        }
        if(i == '.') //checks if it's at a period, if so, it checks if it's at the end of the sentence
                                    //if it is, it breaks out of the loop, which means it doesn't capitalize nothing,
                                    //if it's not the end of the String, it capitalizes 2 spaces over.
        {
            if(i == userCharArray.length)
            {
                break;
            }
            userCharArray[i + 2] = Character.toUpperCase(userCharArray[i + 2]);
        }
    }
    System.out.println(userCharArray);
}

}

再说一遍，我知道它很可能很乱，我再怎么强调也不为过，我稍后会处理它。

请友善一点，这是我的第一个"大"项目。

Answer 1

您可以这样做。。。

 if (Character.isLetter(str.charAt(0))){
     //change the first char to upper case
     str = str.substring(0,1).toUpperCase() + str.substring(1);
 }

其中str是使用的字符串的变量名

这里有另一种方法可以修复字符串，使句点后的字母始终大写，而不是遍历整个字符串并始终检查下一个字母在句点后的位置（因为它可能在句点后出现任意数量的空格）。

//split all sentences and put them into an array
String[] tokens = str.trim().split("\.");
//initialize a result string
String resultString = " ";
//loop through every sentence capitalizing the first character.
for(int i = 0; i<tokens.length; i++){
   //first trim off any whitespace that may occur after period...
   tokens[i] = tokens[i].trim();
   //then capitalize the first letter of every sentence
   tokens[i] = tokens[i].substring(0,1).toUpperCase() + tokens[i].substring(1);
   //then add the sentence with the upperCase first character to your result string
   resultString += " " + tokens[i] + ".";
}
//once out of loop, resultString has the contents of all the sentences with a capital letter to begin the sentence. Notice I use str for my string name, you use s

Answer 2

您可以这样做。

boolean b = Character.isLetter(arr[0]);

其中arr是字符数组或

boolean b = Character.isLetter(s.charAt(0));

如果您有一个字符串s而不是一个char数组。