2、往数组int array[] = {1,2,3,4,5,6,7}第3个位置插入一个数8,最后的结果应该为{1,2,3,8,4,5,6,7}

快来打我* 2022-07-14 14:24 92阅读 0赞

采用循环（未使用Java API）

public static void main(String[] args) {
            /*
             * 2、往数组int array[] = {1,2,3,4,5,6,7}
             * 第3个位置插入一个数8,最后的结果应该为{1,2,3,8,4,5,6,7}
             */
            int array[] = {
       1,2,3,4,5,6,7};
            int arr[] = new int[array.length+1];
    
            Scanner sc = new Scanner(System.in);
            System.out.print("请输入要插入的整数：");
            int number = sc.nextInt();
    
            for (int i = 0; i < array.length; i++) {
                arr[i] = array[i];
            }
    
            for (int i = arr.length-1; i >=4; i--) {
                int temp = arr[i];
                arr[i] = arr[i-1];
                arr[i-1] = temp;
                if(i==4){
                    arr[i-1] = number;
                }
    
            }
    
            for(int i = 0; i < arr.length; i++){
                System.out.println(arr[i]);
            }
        }

利用集合的方式：

public static void main(String[] args) {
    
            ArrayList<Integer> list = new ArrayList<>();
    //      int array[] = {1,2,3,4,5,6,7};
    //      list.add(array);
            list.add(1);
            list.add(2);
            list.add(3);
            list.add(4);
            list.add(5);
            list.add(6);
            list.add(7);
            System.out.println(list);
    //      ArrayList list2 = new ArrayList();
    //      list2.add(8);
    //      list.addAll(3, list2);
            list.add(3, 8);
            System.out.println(list);
    
    
            //遍历方法一：
            for (int i = 0; i < list.size(); i++) {
    
                Object obj = list.get(i);
                System.out.print(obj + ", ");
            }
            System.out.println();
            //遍历方法二：
            for (Object object : list) {
    
                System.out.print(object + ", ");
            }
            System.out.println();
            //遍历方法三：
            Iterator it = list.iterator();
            while(it.hasNext()){
                Object obj = it.next();
                System.out.print(obj + ", ");
            }
            System.out.println();
        }