Initializing Arrays with numbers from file

807569

How can I initialize array with numbers from file, when I don't know how many numbers are in this file?

791266

Use a list instead, e.g. ArrayList or LinkedList.

Kaj

807569

But this is part of my school project. and I can't use this classes.

807569

The better way is to use the list as explained earlier. Since you can't do that you can try the following methodology:

public class NumbersFromFile
{
  private int[] data = new int[0];

  public NumbersFromFile()
  {
  }

  public inputNumber(int num)
  {
    // Expand your array
    int[] tmp = new int[data.length + 1];

    // copy
    System.arraycopy(data, tmp, 0, data.length);

    // add your value to the end
    tmp[tmp.length - 1] = num;

    // swap
    data = tmp;
  }
}

That is the basic way to illustrate how to do it. A better way would be to use a larger size array and only copy as necessary (when it fills up) and only return the size array you need at the end.

807569

Back when I was in university I generally countered this with "what is the class library for?"