Arraylist of arraylist

ArrayList

// THIS IS OKAY:
ArrayList arrayList = new ArrayList();

Source: dummies.com

Arraylist of arraylist

public static void main(String[] args) {
    ArrayList<ArrayList<Integer>> outer = new ArrayList<ArrayList<Integer>>();
    ArrayList<Integer> inner = new ArrayList<Integer>();        

    inner.add(100);     
    inner.add(200);
    outer.add(inner); // add first list
    inner = new ArrayList<Integer>(inner); // create a new inner list that has the same content as  
                                           // the original inner list
    outer.add(inner); // add second list

    outer.get(0).add(300); // changes only the first inner list

    System.out.println(outer);
}

Source: stackoverflow.com

Similar codes

0 vote270 views2 answers
Convert
Java
0 vote287 views2 answers
How to set edittext color in android
Java
1 vote265 views1 answer
Java initialize array with same value
Java
0 vote266 views2 answers
Final finally finalize
Java
283 votes420 views9 answers
Chess
Java
0 vote250 views1 answer
2771270897
Java
0 vote261 views1 answer
Compare list from db and list from request
Java
1 vote268 views1 answer
Java jackson cast to list
Java
1 vote257 views1 answer
Set method in listiterator in java
Java
1 vote260 views1 answer
Remove duplicates from arraylist in android
Java