JAVA复制数组的三种方法

public class test01_ArraysCopy {
    public static void main(String[] args) {
        //1.用for循环复制数组
        int [ ] arr={1,2,3,4,5,6,7,8,9};
        int [ ] arr1=new int[arr.length];
        for (int i = 0; i <arr.length ; i++) {
            arr1[i]=arr[i];
            System.out.print(arr[i]+" ");
        }
        System.out.println(Arrays.toString(arr1));


        System.out.println("------------------------------------");

        //2.Arrays.copyOf方法也可以用来复制数组
        int [ ] arr2={1,2,3,4,5,6,7,8,9};
        int [ ] arr3=Arrays.copyOf(arr2,arr2.length);
        System.out.println(Arrays.toString(arr2));

        System.out.println("------------------------------------");

        //System.arraycopy(源数组, 源数组中的起始位置, 目标数组, 目标数组中的起始位置, 要复制的数组元素的数量);
        int[] arr4 = new int[]{1,32,23,231,432,123,12};
        int[] arr5 = new int[arr4.length];
        System.arraycopy(arr4, 2, arr5, 0, arr4.length-2);
        System.out.println(Arrays.toString(arr5));

    }


}