我想将最大编号从一个文件复制到另一个文件？但是，找不到最大编号

Question

I tried to take the data taken from a file, convert it to a character array, find the largest number from file first.txt and copy the result to file second.txt. However, when I compile and run the program the following problems occur:

1. Does not take two digit Arrays.
2. It also does not take more than 5 numbers from the text file
3. Whenever I compile the program it writes the last number in the second file.

This is the code I am working with.

BufferedReader out = new BufferedReader(new  FileReader("first.txt"));
PrintWriter in = new PrintWriter(new FileWriter("second.txt"));
char[] array = null;
String str = " ";
str = out.readLine();
array = str.toCharArray();
char max = array[0];

for (char c : array) {
    if(c > max);
    max = c;
    in.write(max);

Answer 1

If it is not necessary to use char array, better don't. Use String as it is easier in handling. String.split() is a good way to split first.txt and Integer.parseInt() can help you with turning a String to integer. You can store them on an array and sort the array afterwards.

Answer 2

(But,If I try to put Numbers like below- 1 2 3 4 Then it takes only one number that is 1.)

BufferedReader out = new BufferedReader(new FileReader("Nos for fnding highest.txt")); BufferedWriter in = new BufferedWriter(new FileWriter("third.txt")); String str = " "; str = out.readLine(); String []numbers = str.split(" "); //array = str.toCharArray(); //char max = array[0]; int[] array = new int[numbers.length]; int count = 0; //converting the string to integer format for(String strs : numbers){ array[count++] = Integer.parseInt(strs); } int max = array[0]; for (int c : array) { if(c > max) max = c;

        }
    in.write(new Integer(max).toString());
        out.close();
        in.close();