Question

Right now I want to store a text file that goes like this:

1 apple

2 banana

3 orange

4 lynx

5 cappuccino

and so on into a data structure. Would the best way of doing this be mapping the int to the string somehow, or should I make an arraylist? I’m supposed to, when I store the words themselves, disregard the int and any whitespace, and keep only the word itself. How do I disregard the int when reading in lines? Here is my hacked together code right now:

  public Dictionary(String filename) throws IOException {
  if (filename==null)
      throw new IllegalArgumentException("Null filename");
  else{
      try {
            BufferedReader in = new BufferedReader(new FileReader(filename));
            String str;
            int numLines=0;
            while ((str = in.readLine()) != null) {
                numLines++;
            }
            String[] words=new String[numLines];
            for (int i=0; i<words.length;i++){
                words[i]=in.readLine();
            }

            in.close();
        } catch (IOException e) {
    }
  }

}

Thank you in advance for the help!!

Answer 1

Just implement the power of the regular expression:

List texts<String> = new ArrayList<String>();
Pattern pattern = Pattern.compile("[^0-9\\s]+"); 
String text = "1 apple 2 oranges 3 carrots"; 
Matcher matcher = pattern.matcher(text); 

while (matcher.find()) { 
  texts.add(matcher.group(0)); 
} 

regular expressions are very much popular these days. the compile method is used for compiling your search pattern, with the numbers you see in the parameter is to prevent getting them on your search. So it’s completely safe. use apache’s IOUtilities to convert a text file to String