Insert object into a specified index in an ArrayList

Question

Let's say I have a class called myClass<K,V>. In my class I have an ArrayList called myArrayList.

How would I go about placing something of type V into a certain spot in the array list. For example, trying something like myArrayList[place] = vThing doesn't seem to work.

Here's the declaration:public ArrayList<V> myArrayList[];. I added myArrayList.add(place, value); , but I'm getting an error that says "cannot invoke add(int, V) on the array type ArrayList[]".

I get it now, I was thinking that an arraylist would work like an array, but it appears as though is works more like a list.

docs.oracle.com/javase/7/docs/api/java/util/List.html#add(E) — SLaks
– SLaks, Commented Dec 4, 2013 at 18:16

Jeroen Vannevel · Accepted Answer · 2013-12-04 18:25:37Z

1

An ArrayList has an overload for the add() method

add(int index, E element)

for this exact purpose. You cannot access it using square brackets like an array.

Adding a generic type has nothing to do with this (assuming you define your ArrayList as List<V> myArrayList = new ArrayList<>()).

Responding to your edit. Change

public ArrayList<V> myArrayList[]

to

public ArrayList<V> myArrayList

If you put square brackets there, it will consider it.. Hell, I'm not even sure. It's just bad practice. I'm guessing an array of arraylists? Or an arraylist of arrays?

edited Dec 4, 2013 at 18:25

answered Dec 4, 2013 at 18:17

Jeroen Vannevel

44.6k25 gold badges113 silver badges174 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jeroen Vannevel Over a year ago

@user2793388: you can accept it as an answer if you deem it worthy as such.

Shamse Alam · Accepted Answer · 2013-12-04 18:25:15Z

0

add(int index, E element)

Inserts the specified element at the specified position in list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

answered Dec 4, 2013 at 18:25

Shamse Alam

1,3151 gold badge10 silver badges21 bronze badges

Comments

Yetti · Accepted Answer · 2013-12-04 18:26:39Z

0

I would advice to learn searching in http://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html (for example) you can find there all available methods.

For example :

void    add(int index, E element)

Inserts the specified element at the specified position in this list.

answered Dec 4, 2013 at 18:26

Yetti

3271 gold badge4 silver badges17 bronze badges

Collectives™ on Stack Overflow

Insert object into a specified index in an ArrayList

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related