how to add value to arraylist at index 0 code example
Example 1: ArrayList add(int index, E element) method in java
import java.util.ArrayList;
public class ArrayListAddMethodExample
{
public static void main(String[] args)
{
// creating an empty ArrayList with initial capacity
ArrayList<Integer> al = new ArrayList<Integer>(6);
al.add(12);
al.add(14);
al.add(16);
al.add(18);
al.add(20);
// adding element 15 at fourth position
al.add(3, 15);
for(Integer number : al)
{
System.out.println("Number: " + number);
}
}
}
Example 2: arraylist insert at position
//Insert a value by using arrayName.add(index, value)
//Will not remove current element at index. Will simply move all elements to
//the right.
import java.util.ArrayList;
public class main{
public static void main(String[] args){
ArrayList<Integer> list = new ArrayList<Integer>();
list.add(0);
list.add(1);
list.add(2);
list.add(3);
list.add(4);
list.add(5);
list.add(0, 100);
//enhanced for loop will print all elements of the ArrayList
for(int element : list){
System.out.print(list + ", ");
}
//Expected output: "100, 0, 1, 2, 3, 4, 5, "
}
}