Reading only the integers from a txt file and adding the value up for each found

Question

I am trying to read a txt file that contains strings with integers. I would like to be able to get just the integers from this file and add the value each to create a total.

Answer 1

You have done all the work and stuck with simple addition. Declare a variable total and add integers(values) to it. In the code block, if(scan.hasNextInt()) add the following statement : total += scan.nextInt().

Do not forget to declare the variable before hand.

Answer 2

Your file name looks incorrect change it to :-

 Scanner scan = new Scanner(new File("validtest.txt"));

Then i believe you already have logic just uncomment that adding part in your code.

  if (scan.hasNextInt()) {
                System.out.println("Found :" + scan.nextInt());
                goals = scan.nextInt();
                total+= goals;
             }

Answer 3

Instead of printing out the integer, you can add them to a list.

List<Integer> goals = new ArrayList<Integer>();
goals.add(scan.nextInt());

And then add them up!

Or if you don't need access to them individually, you can simply,

total = total + scan.nextInt(); //OR total += scan.nextInt();

In your if(scan.hasNextInt()) block

Answer 4

your code doesn't really do what your comments claim it does maybe you want this?

    import java.util.regex.Pattern;

    public void goalCount(){
                int goals=0;// i dont see where this is used
                double total=0;
             try{
                Scanner scan = new Scanner(new File("validtest.txt.txt"));
                while (scan.hasNext()) {
                    String temp=scan.next();
                     if (isInteger(temp)) {
                         total+=Integer.ParseInt(temp);
                        System.out.println("Found :" + temp);
                     }
                     else{
                    System.out.println("Not Found :" + temp);}
                  }
                  scan.close();
               }
            catch(Exception e){

            }
               System.out.println("Total Goals:"+total); 
            }

    }
    public boolean isInteger( String input ) {
        Pattern p=Pattern.compile("-?\\d+");
        return input.matches(p.pattern());}
    }
    }

Answer 5

Edit:
You'll have to excuse me, that method will not work. What you need to do is read one line at a time, then split the line by each space, to get an array of words. From there you can identify integers and store the value.

final static String filename = "FILENAME.txt";

   public static void main(String[] args) {

      Scanner scan = null;
      File f = new File(filename);
      try {
         scan = new Scanner(f);
      } catch (FileNotFoundException e) {
         System.out.println("File not found.");
         System.exit(0);
      }

      int total = 0;
      boolean foundInts = false; //flag to see if there are any integers

      while (scan.hasNextLine()) { //Note change
         String currentLine = scan.nextLine();
         //split into words
         String words[] = currentLine.split(" ");

         //For each word in the line
         for(String str : words) {
            try {
               int num = Integer.parseInt(str);
               total += num;
               foundInts = true;
               System.out.println("Found: " + num);
            }catch(NumberFormatException nfe) { }; //word is not an integer, do nothing
         }
      } //end while 

      if(!foundInts)
         System.out.println("No numbers found.");
      else
         System.out.println("Total: " + total);

      // close the scanner
      scan.close();
   }