CODEWITHSUNDEEP
javaarraylist
user3416645
user3416645

Reputation: 23

Working with ArrayList and Reversing files

I am currently stuck on what to do with my code. I must open a file and then inside of a while loop I have to get each line one at a time then I must reverse it then print it. This is what I have so far:

 public class ReverseFileContents
  { 
    public static void main(String[] args) throws FileNotFoundException
    {
      Scanner myScanner = new Scanner(System.in);
      Scanner diskScanner = new Scanner (new File("reverse"));
      while (inputFile.hasNextLine())
      {
      }
    }
  }

This is all I have after this point I am lost and just don't know which direction to go with the arraylist and using BufferedReader. Could anybody help me further this along?

Upvotes: 0

Views: 90

Answers (2)

Dileep
Dileep

Reputation: 5440

This will do i believe..!!

File file = new File(filename);
Scanner in = new Scanner(file);
 while (in.hasNextLine()){
System.out.println(reverse(in.nextLine()));
}

public String reverse(String text){
String reverse="";
for( int i = text.length - 1 ; i >= 0 ; i-- ) 
       reverse = reverse + text.charAt(i);;
return reverse;
}

Upvotes: 1

leigero
leigero

Reputation: 3283

This sounds like a homework assignment, and so I'm going to avoid giving you the algorithm you need.

Here are some tips about getting a file and going through it line by line:

File filename = new File("file.txt");
Scanner file = new Scanner(filename);

ArrayList<String> lines = new ArrayList<String>();
while(file.hasNextLine()){
    String line = file.nextLine();
    //You can manipulate the line in here and do whatever you want
    //This can also store the data into an ArrayList for later if you need
    myReverse(line);
    lines.add(line);
}

Here is a starting point for a reverse method. There are dozens of ways to accomplish this task:

public void myReverse(){
    //convert the string into an array
    //move through the array backwards printing the values
}

Upvotes: 0

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