Significance of 'In' in Java

Question

I've copied the following method from page 173 of this book.

public class ThreeSum
{
  public static int count(int[] a)
  { // Count triples that sum to 0.
    int N = a.length;
    int cnt = 0;
    for (int i = 0; i < N; i++)
      for (int j = i+1; j < N; j++)
        for (int k = j+1; k < N; k++)
          if (a[i] + a[j] + a[k] == 0)
            cnt++;
    return cnt;
  }

  public static void main(String[] args)
  {
    int[] a = In.readInts(args[0]); // error here
    StdOut.println(count(a)); // and here
  }
}

The In.readInts causes an error. Do I need to be including a library to access the 'In' object? (third last line)

import scanner. maybe. look at the book, they probably use the same method for input all around, so just check the beginning. — elyashiv, Aug 03 '16 at 13:47
It seems you copied code from some where. In is nothing in java. In in the example you copied from could be a stream or some custom class. — kosa, Aug 03 '16 at 13:47
answer is here: [http://stackoverflow.com/questions/16207427/compile-error-cannot-find-symbol-in-stdin-and-stdout] — Jordi Flores, Aug 03 '16 at 13:47

score 1 · Answer 1 · answered Aug 03 '16 at 13:48

1

Yes, In is not a original Java class, but probably an API/Library class from your book. Look at one of the first pages, probably you will find some information about the class.

answered Aug 03 '16 at 13:48

Adrian K.

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Significance of 'In' in Java

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