ArrayList in ArrayList<String>

Question

ArrayList<ArrayList<String>> mainlist = new ArrayList<ArrayList<String>>();
ArrayList<String> childlist = new ArrayList<String>();
for (int i = 0; i < 3 i++){
 String chlidtext = chlidlist + String.valueof(i);
 String maintext = mainlist +String.Valueof(i);
 childlist.add(chlidtext);
 mainlist.add(maintext);
}

 return mainlist;

i dont have an idea how to get 3rd element in every chlidlist ?

• Sandeep Pathak: mainlist.add(maintext) --> you are adding String in place of arrayList.
• G_S: You are having only 3 child nodes? (start the i value from 2 and then increment it by 3 )
• besworland: Are you sure that this line mainlist.add(maintext); is OK? I would say mainlist.add(childlist).
• Bucks: its not working if i use for/for each loop it display one 1st mainlist 3rd childlist item 3x times
• android: You may get exception because you should add ArrayList<String> to mainlist, but you are adding String here. And you can get 3rd element of an arraylist by giving its index to get method. mainlist.get(2) will return 3rd element.

Answer 1

You can access 3rd element of childList by:

mainList.get(index).get(2); // Here 1st get() will get the 1st element of mainList which conatins 1st child element and 2nd get() will get the 3rd element of childlist.

• Bucks: i tried for(i=0;i<3;i++){ mainlist.get(i).get(2); } it will display mainlist 1 chlidlist 3rd item. 3x times