arraycopy效率比较

import java.util.Date;

public class TestArrayCopy {
public static void main(String[] args) {

Date d1 = new Date();
int[] arr = new int[10000000];
for(int i = 0; i < 10000000; i++) {
arr[i] = i;
}
Date d2 = new Date();

System.out.println(d2.getTime() - d1.getTime());

int[] arr2 = new int[10000000];
Date d3 = new Date();
System.arraycopy(arr,0, arr2, 0, 10000000);
Date d4 = new Date();
System.out.println(d4.getTime() - d3.getTime());
}
}