[SOLVED] ArrayList element to int

[grahamb314]

Hi all,

I am trying to get a certain element of my ArrayList to an int:

ArrayList cities = new ArrayList<Integer>();
while (cities.size() != 0) { //while not null (ATM it will always be null till finished writing the loop)
        int s = 0;
        int one = cities.get(d);  //this is where I get the error
        cities.add(s,"x");
        System.out.println("___________");
        System.out.println(cities.get(s));
    }

I get an error: Found Object, required int
(Please note that there may be problems with my loops (its not finished yet) All i need to know is how to get the element d or even element 0 or 1 to save as type int in variable "one"

Any thoughts?

Thanks!

[emceenugget]

ArrayList holds Objects only. You are trying to get an int from an ArrayList. That is why you get your error.

Integer is a wrapper class for the the int primitive.

[Nicholas Jordan]

int city;
//......some code.....
Integer nextCity = ( Integer ) arrayList.getSomeCity(index);
city = nextCity.toInt();

or something like that. As you say, you are still working on the code.

[grahamb314]

Code:

int city; //......some code..... Integer nextCity = ( Integer ) arrayList.getSomeCity(index); city = nextCity.toInt();

or something like that. As you say, you are still working on the code.

Thanks for that.
I'm not sure if it what I am looking for:
What I want to do is save the 1st element of the arrayList to an int variable.
I dont mind changing the type of the arrayList, eg back to a String

Here is more complete code:

ArrayList cities = new ArrayList<Integer>();
x=1
s=0
cities.add(s,"x"); // add "1" at position 0
// now I want to save whatever is at positin s to an int variable
/i tried: int number = cities.get(s);
but the complier says I cant due to incompatable file types/

I couldnt seem to get the above sugestions to work.

Thanks so far!

[Fubarable]

Your code is not kosher and in fact contains a gross error.

You first create an ArrayList of Integer called cities, and then add a String object to this list via this call:

cities.add(s,"x");

Why are you doing this?

You know of course that "x" is a string and has absolutely no relationship to the variable x that holds an int, correct?

[grahamb314]

Your code is not kosher and in fact contains a gross error.

You first create an ArrayList of Integer called cities, and then add a String object to this list via this call:

Code:

cities.add(s,"x");

Why are you doing this?

You know of course that "x" is a string and has absolutely no relationship to the variable x that holds an int, correct?

Either way I think the problem remains, I think this should solve the confusion?

ArrayList cities = new ArrayList<Integer>();
int x=1
s=0
cities.add(s,x); // add "1" at position 0
// now I want to save whatever is at positin s to an int variable
//i tried: int number = cities.get(s);
//but the complier says I cant due to incompatable file types

[Fubarable]

At this point, I recommend that you show us a small compilable program that reproduces your problem. Something on this order would help us help you:

import java.util.ArrayList;
import java.util.List;

public class TestArrayList {
  private static final int MAX = 10;

  public static void main(String[] args) {
    List<Integer> cities = new ArrayList<Integer>();
    for (int i = 0; i < MAX; i++) {
      cities.add(i);
    }
    
    for (int i = 0; i < cities.size(); i++) {
      int myInt = cities.get(i);
      System.out.println(myInt);
    }
    
  }
}

[grahamb314]

Hi all,
this seems to have done the trick!

Integer curr = ( Integer ) cities.get(i);

Although I dont know what it is doing?

Cheers!

[Fubarable]

It's casting the object returned from the cities ArrayList into an Integer. But I'm confused as this should be completely unnecessary if you are using a generic ArrayList that was declared ArrayList<Integer> to begin with.

[grahamb314]

It's casting the object returned from the cities ArrayList into an Integer. But I'm confused as this should be completely unnecessary if you are using a generic ArrayList that was declared ArrayList<Integer> to begin with.

That same confusion was why I posted

this seems to have done the trick and thanks for explaining the casting!