CODEWITHSUNDEEP
javaclassobjectarraylistnested
nlreturns
nlreturns

Reputation: 161

Java Nested ArrayList returns Object

I have a nested ArrayList

ArrayList<ArrayList<MenuItem>> MenuList = ArrayList<ArrayList<MenuItem>>()

MenuItem is my class containing the item name and task(int). I'm using a few buttons to iterate through my Menu, and when I press the "enter" key I'd like to access the currently selected MenuItem.

The code is as following;

// enter button pressed
if(buttonStateEnter != lastButtonStateEnter){
   // changes
   // get current menu
   ArrayList currentMenuList = MenuList.get(currentMenu);

   // get menuItem obj
   Object test = currentMenuList.get(0);

   System.out.println(test.getClass());

   // get the task (int)
   //int changeTask = subNest.getTask();

   lastButtonStateEnter = buttonStateEnter;
   redraw = true;
}

I want to create MenuItem test rather than Object test, because I cannot access my methods this way. test.getClass() returns Class MenuItem. Putting MenuItem test in code compiles with the error

java.lang.Object cannot be converted to MenuItem

Upvotes: 1

Views: 166

Answers (3)

asingh
asingh

Reputation: 11

// enter button pressed
if(buttonStateEnter != lastButtonStateEnter){
   // changes
   // get current menu
   ArrayList <MenuItem> currentMenuList = MenuList.get(currentMenu);

   // get menuItem obj
   MenuItem test = currentMenuList.get(0);

   System.out.println(test.getClass());

   // get the task (int)
   //int changeTask = subNest.getTask();

   lastButtonStateEnter = buttonStateEnter;
   redraw = true;
}

This should work...

Upvotes: -1

Shiladittya Chakraborty
Shiladittya Chakraborty

Reputation: 4418

// enter button pressed
if(buttonStateEnter != lastButtonStateEnter) {
  // changes
  // get current menu
  ArrayList<MenuItem> currentMenuList = MenuList.get(currentMenu);

  // get menuItem obj
  MenuItem test = currentMenuList.get(0);

  System.out.println(test.getClass());

  // get the task (int)
  //int changeTask = subNest.getTask();

  lastButtonStateEnter = buttonStateEnter;
  redraw = true;
}

Upvotes: 1

SacJn
SacJn

Reputation: 777

List<MenuItem> Menu = new ArrayList<MenuItem> () should help.

Or you must typecast it with get operation as following:
(MenuItem)Menu.get(

But the second option shall give you warning to make sure you are typecasting to the right type

Upvotes: 3

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