'System.arraycopy ()' 要比通過迴圈來複制陣列快的多。

例子：

public class IRB

{

   void method () {

       int[] array1 = new int [100];

       for (int i = 0; i < array1.length; i++) {

           array1 [i] = i;

       }

       int[] array2 = new int [100];

       for (int i = 0; i < array2.length; i++) {

           array2 [i] = array1 [i];                 // Violation

       }

    }

}

更正：

public class IRB

{

   void method () {

       int[] array1 = new int [100];

       for (int i = 0; i < array1.length; i++) {

           array1 [i] = i;

       }

       int[] array2 = new int [100];

       System.arraycopy(array1, 0, array2, 0, 100);

    }

}

參考資料：

http://www.cs.cmu.edu/~jch/java/speed.html