計數字母出現

Question

程序需要計算並顯示指定的charector出現在文本文件中的次數。

目前總數爲零。我不是如果我應該使用不同的循環，我也嘗試使用'for'循環。

// Hold user input and sum 
String fileName; // Holds the name of the file 
String letter;  // Letter to search for in the file 
int total = 0;  // Holds the total number of characters in the file 


// Get the name of the file and character from the user 
fileName = JOptionPane.showInputDialog("Please enter the name of a file:"); 
letter = JOptionPane.showInputDialog("Please enter a letter contained in the string"); 


// Open the file for reading 
File file = new File(fileName);   
Scanner inputFile = new Scanner(file); // Declare new scanner object for file reading 


// Set accumulator to zero 
int count = 0; 

if (inputFile.nextLine().equalsIgnoreCase(letter)) {         

    count++;   // add letter occurrence 

    total += count; // add the letter occurrence to the total 
} 

Answer 1

BufferedReader reader = new BufferedReader(new FileReader("somefile.txt")); 
    int ch; 
    char charToSearch='a'; 
    int counter=0; 
    while((ch=reader.read()) != -1) { 
     if(charToSearch == (char)ch) { 
      counter++; 
     } 
    }; 
    reader.close(); 

    System.out.println(counter); 

I這有什麼幫助？

Answer 2

這個答案假定您的文本文件中的每行只包含一個字母，就像您的問題所示。

你需要用你的if語句在一個循環中你目前只檢查文件的第一行：

 while(inputFile.hasNext()) { 
     if (inputFile.nextLine().equalsIgnoreCase(letter)) {         

      count++;   // add letter occurrence 

      total += count; // add the letter occurrence to the total 
     } 
    } 

你也可以更換：

count++; 
total+= count; 

只

total++; 

Answer 3

String line="" 
while(inputFile.hasNext()) { 
    line = inputFile.nextLine(); 
    for(int i=0; i<line.length(); i++){ 
    if (line.charAt(i)== letter)          
     count++;   

} 
} 

Answer 4

有錯誤你code.Correct代碼如下─

String fileName; // Holds the name of the file 
    String letter;  // Letter to search for in the file 

    // Get the name of the file and character from the user 
    fileName = "C:\\bin\\GWT.txt"; 
    letter = "X"; 


    // Open the file for reading 
    File file = new File(fileName);   
    Scanner inputFile = new Scanner(file); // Declare new scanner object for file reading 


    // Set accumulator to zero 
    int count = 0; 
    while(inputFile.hasNext()) { 
     if (inputFile.nextLine().toLowerCase().contains(letter.toLowercase())) { 
      count++;   // add letter occurrence 
     } 
    } 
    System.out.println(count);