使用for循环和System.arraycopy（）方法复制数组

import java.util.Arrays;


public class Main {

  public static void main(String[] args) {/**来 自 nowjava**/

    // Have an array with 5 elements

    int[] data = {1, 2, 3, 4, 5 };


    // Expand the data array to 7 elements

    int[] d1 = expandArray(data, 7);


    // Truncate the data array to 3 elements

    int[] d2 = expandArray(data, 3);


    System.out.println("Original Array: " + Arrays.toString(data));

    System.out.println("Expanded Array: " + Arrays.toString(d1));

    System.out.println("Truncated Array: " + Arrays.toString(d2));// 来自 n o w j a v a . c o m


    // Copy data array to new arrays

    d1 = new int[9];

    d2 = new int[2];

    System.arraycopy(data, 0, d1, 0, 5);

    System.arraycopy(data, 0, d2, 0, 2);

       

    System.out.println("Original Array: " + Arrays.toString(data));

    System.out.println("Expanded Array: " + Arrays.toString(d1));

    System.out.println("Truncated Array: " + Arrays.toString(d2));   

  }


  public static int[] expandArray(int[] oldArray, int newLength) {

    int originalLength = oldArray.length;   

    int[] newArray = new int[newLength];        

    int elementsToCopy = 0;