OnJava8-Examples/onjava/Range.java

// onjava/Range.java
// <20>2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// Array creation methods that can be used without
// qualifiers, using static imports:
package onjava;

public class Range {
  // Produce a sequence [0..n)
  public static int[] range(int n) {
    int[] result = new int[n];
    for(int i = 0; i < n; i++)
      result[i] = i;
    return result;
  }
  // Produce a sequence [start..end)
  public static int[] range(int start, int end) {
    int sz = end - start;
    int[] result = new int[sz];
    for(int i = 0; i < sz; i++)
      result[i] = start + i;
    return result;
  }
  // Produce a sequence [start..end) incrementing by step
  public static int[] range(int start, int end, int step) {
    int sz = (end - start)/step;
    int[] result = new int[sz];
    for(int i = 0; i < sz; i++)
      result[i] = start + (i * step);
    return result;
  }
}