读取文本文件并计算文本文件中的空格数

Question

我需要 Java 中的程序来获取一个文本文件，读取该文本文件，计算并重现该文本文件中的空格数量

这是我目前拥有的代码

import java.io.File;  //import the file class
import java.io.FileNotFoundException; //import this class to handle errors
import java.util.Scanner; //import the scanner class to read the file

public class whitespaceReader {

    public static void main(String[] args) {
        try {

            File myFile = new File("aliceInWonderland.txt");

            Scanner reader = new Scanner(myFile);

            int space = 0;
            int i = 0;
            String word;

            word = reader.nextLine();

            while (i < word.length()){
                char a = word.charAt(i);

                if(a == '//tried to use empty brackets here, did not work') {
                    space++;
                }
                i++;
            }
            System.out.println("amount of white space is: " + space);

        } catch (FileNotFoundException e) {
            System.out.print("Uh oh! Something went wrong");
            e.printStackTrace();
        }
    }
}

Answer 1

像这样使用 BufferedReader 读取行。

final String fileName = "Path to your file"
final char countedChar = ' ';
int characterCount = 0;
BufferedReader br = new BufferedReader(new FileReader(fileName));
String line = null;
while((line = br.readLine()) != null){
 for(int i = 0; i < line.length(); i++){
   if(countedChar == line.charAt(i)){
     characterCount++;
   }
 }
}
System.out.println(characterCount);

Answer 2

你可以这样做

public static void main(String[] args) {
    try {

        File myFile = new File("aliceInWonderland.txt");

        Scanner reader = new Scanner(myFile);

        int space = 0;
        int n = 0;
        String word = "";

        while(reader.hasNextLine()){
            word += reader.nextLine();
        }
        n = word.length();

        space = word.replace(" ","").length();
        space = n - space;
        System.out.println("amount of white space is: " + space);

    } catch (FileNotFoundException e) {
        System.out.print("Uh oh! Something went wrong");
        e.printStackTrace();
    }
}

只需要用不带空格的句子长度减去句子长度即可。

不需要循环

Answer 3

如果您使用 class java.util.Scanner 并且您只计算 space 个字符，即 Unicode 代码点为 32（十进制）的字符，并且您使用的是至少 JDK 9，那么你可以简单地调用方法 findAll 并计算该方法返回的流中元素的数量。

import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Scanner;

public class WhitespaceReader {

    public static void main(String[] args) {
        Path path = Paths.get("aliceInWonderland.txt");
        try (Scanner reader = new Scanner(path)) {
            long space = reader.findAll(" ")
                               .count();
            System.out.println("amount of white space is: " + space);
        }
        catch (IOException xIo) {
            xIo.printStackTrace();
        }
    }
}

注意上面的代码使用了try-with-resources来保证Scanner关闭，防止资源泄露

另请注意，我将 class 名称更改为 WhitespaceReader 以遵守 java naming conventions。

如果要统计全部whitespace characters, simply change the string argument (to method findAll) to \s+. Refer to javadoc for class java.util.regex.Pattern

Answer 4

   import java.io.IOException;
   import java.nio.file.Files;
   import java.nio.file.Paths;
    
    public class NumberOfSpacesInAFile {
    
        public static long noOfSpaces = 0;
        
        public static void main(String[] args) throws IOException {
            
            Files.lines(Paths.get("file.txt"))
             .map(lines->{noOfSpaces = noOfSpaces + lines.chars().filter(eachChar->eachChar==32).count();return lines;})
             .count();
            
            System.out.println(noOfSpaces);

        }
    }

读取文本文件并计算文本文件中的空格数

Read a text file and count the number of white spaces in the text file

java

whitespace