OnJava8-Examples/arrays/CopyingArrays.java

// arrays/CopyingArrays.java
// (c)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.
// Using System.arraycopy()
import java.util.*;

public class CopyingArrays {
  public static void main(String[] args) {
    int[] i = new int[7];
    int[] j = new int[10];
    Arrays.fill(i, 47);
    Arrays.fill(j, 99);
    System.out.println("i = " + Arrays.toString(i));
    System.out.println("j = " + Arrays.toString(j));
    System.arraycopy(i, 0, j, 0, i.length);
    System.out.println("j = " + Arrays.toString(j));
    int[] k = new int[5];
    Arrays.fill(k, 103);
    System.arraycopy(i, 0, k, 0, k.length);
    System.out.println("k = " + Arrays.toString(k));
    Arrays.fill(k, 103);
    System.arraycopy(k, 0, i, 0, k.length);
    System.out.println("i = " + Arrays.toString(i));
    // Objects:
    Integer[] u = new Integer[10];
    Integer[] v = new Integer[5];
    Arrays.fill(u, 47);
    Arrays.fill(v, 99);
    System.out.println("u = " + Arrays.toString(u));
    System.out.println("v = " + Arrays.toString(v));
    System.arraycopy(v, 0, u, u.length/2, v.length);
    System.out.println("u = " + Arrays.toString(u));
  }
}
/* Output:
i = [47, 47, 47, 47, 47, 47, 47]
j = [99, 99, 99, 99, 99, 99, 99, 99, 99, 99]
j = [47, 47, 47, 47, 47, 47, 47, 99, 99, 99]
k = [47, 47, 47, 47, 47]
i = [103, 103, 103, 103, 103, 47, 47]
u = [47, 47, 47, 47, 47, 47, 47, 47, 47, 47]
v = [99, 99, 99, 99, 99]
u = [47, 47, 47, 47, 47, 99, 99, 99, 99, 99]
*/