CODEWITHSUNDEEP
java
Babar Sanah
Babar Sanah

Reputation: 553

Insert data in an array list java

I have two lists one is feature and has a placement number based on which i insert data in sorted list e.g if placement number is 5 data will be added in 5th position .i want to add data at 5th postion and to move data which was at 5th position to next index but in my case it just replace data at 5th position not move current data to next position 

      for (int i = 0; i < featuredList.size(); i++) {

            int n = featuredList.get(i).getPlacementNumber().intValue();
            if (n < sortedList.size()) {

                    sortedList.add(n, featuredList.get(i));


            } else {
                sortedList.add(featuredList.get(i));
            }


        }

Upvotes: 0

Views: 12121

Answers (3)

Hareshkumar Chhelana
Hareshkumar Chhelana

Reputation: 24848

Try to use LinkedList to insertion or deletion between list for better performance then ArrayList : 

private LinkedList<String> linkedList = new LinkedList<String>();

linkedList.add("1");
linkedList.add("2");
linkedList.add("3");
linkedList.add("4");
linkedList.add("5");

// insertion at 3 position
linkedList.add(2,"6");

Upvotes: 1

Pankaj Dubey
Pankaj Dubey

Reputation: 146

Another example which may give you some clue and even easy to run :)

import java.util.ArrayList;


public class Alisttest {
  public static void main(String[] args) {
    ArrayList a = new ArrayList();
    a.add("1");
    a.add("2");
    a.add("3");
    a.add("4");


    System.out.println("a=> "+a.get(2));
    a.add(2, "Pankaj");

    System.out.println("a=> "+a.get(2));
    System.out.println();
    System.out.println("a=> "+a);
}

}

Upvotes: 0

Sumit Singh
Sumit Singh

Reputation: 15896

You should use ArrayList, from add(int index, E element)

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

Make your sortedList as ArrayList:

List<YourType> sortedList= new ArrayList<YourType>();

See the example http://ideone.com/L6hpsf 

String s1 = "s1";
String s2 = "s2";
String s3 = "s3";
List<String> list = new ArrayList<String>();
list.add(s1);
list.add(s3);
list.add(1, s2);
System.out.println(list);

Output: [s1, s2, s3]

Upvotes: 3

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