在数组中添加元素

1.对数组元素进行复制；然后修改指定位置的元素为添加元素

    package Program.product01;

    public class Demo1 {
        public static void main(String[] args) {
            int arrs[] ={1,2,3,4,5,6,7,8};//在3后面加入数字0
            System.out.print("打印交换位置前的字符:\n");
            for(int i =0;i<=arrs.length-1;i++)
            {

                if(i!= arrs.length-1)
                {
                    System.out.print(arrs[i]+",");
                }
                else {
                    System.out.println(arrs[i]);
                }

            }
            int index = 3;//在3的后面插入元素0的下角标

            for(int i = arrs.length-1;i>=index+1;i--)
            {					  //1,2,3,4,5,6,7,8
                					
                arrs[i]=arrs[i-1];//1,2,3,4,4,5,6,7

            }
            arrs[index] =0;


            System.out.print("\n打印交换位置后的字符:\n");
            for(int i =0;i<=arrs.length-1;i++)
            {
                if(i!= arrs.length-1)
                {
                    System.out.print(arrs[i]+",");
                }
                else {
                    System.out.println(arrs[i]);
                }
            }

        }
    }

2. 对一种的方法进行调用：

    package Program.product01;

    public class Demo1 {
        public static void eleIndex(int []arrs,int index,int ele) {//在某个数组的第三个角标下插入某个数
            for (int i = arrs.length - 1; i >= index + 1; i--) {
                arrs[i] = arrs[i - 1];
            }
            arrs[index] = ele;
        }
        public static void main(String[] args) {
            int arrs[] = {1, 2, 3, 4, 5, 6, 7, 8};//在3后面加入数字0
            System.out.print("打印交换位置前的字符:\n");
            for (int i = 0; i <= arrs.length - 1; i++) {

                if (i != arrs.length - 1) {
                    System.out.print(arrs[i] + ",");
                } else {
                    System.out.println(arrs[i]);
                }

            }
            eleIndex(arrs,2,666);
            System.out.print("\n打印交换位置后的字符:\n");
            for (int i = 0; i <= arrs.length - 1; i++) {
                if (i != arrs.length - 1) {
                    System.out.print(arrs[i] + ",");
                } else {
                    System.out.println(arrs[i]);
                }
            }

        }
    }