ArrayList 类型中的方法 set(int, Int)<int> 不适用于 arguments (int, int) 长度无法解析或不是字段</int>

Question

My code is showing:

The method set(int, Int) in the type ArrayList is not applicable for the arguments (int, int) length cannot be resolved or is not a field

but I don't know how to resolve it.

package revision;
import java.util.*;

public class FinalTrace {

    public static <Int> void main(String[] args) {
        // TODO Auto-generated method stub
        ArrayList <Int> list = new ArrayList <Int>();
        list.add(100, null);
        list.add(200, null);
        int num = (int) list.get(1);
        System.out.println("Number at index 1 in your arraylist: " + 
        num);
        
        **list.set(2, 500);
        System.out.print("The current numbers in your arraylist: ");
        for (int i=0; i < list.length; i++)
        System.out.print(list.get(i) + " ");
        System.out.println("\n----------------------");**

        int [] arr = new int[3];
        getValues(arr);
        System.out.print("The numbers of array that you already entered: ");
        for (int i = 0; i < arr.length; i++)
        System.out.print(arr[i] + " ");
        System.out.println("\n----------------------");

        classA obj1 = new classA();
        classA obj2 = new classC();
        classC obj3 = new classC();
        System.out.print(obj2.toString());

        System.out.println("----------------------");
        try
        {
        if (num == 200)
          throw new FinalException();
        }
        finally
        {
        FinalException e;
        System.out.println(e.getMessage());
        }
      }

Answer 1

Fix ArrayList <Int> list = new ArrayList <Int>() to List <Integer> list = new ArrayList <>() . The boxed int is Integer .

Also, Collections to not have length like an array. Correct to list.size()`.