java arrays arraycopy 复制数组

    public static void main(String args[]){
        int[] source = {1,2,3,4,5,6,7};
        int[] target = new int[5];
        System.arraycopy(source,0,target,0,5);// 6,7超出5的长度,被省略了

        System.out.println(Arrays.toString(target));

        for(int i = 0;i < target.length;i++){
            System.out.print(target[i] + "\t");
        }
    }