22. int size()

22. int size()
Returns the number of elements in this list.

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package com.spy.arraylist.method;
 
import java.util.ArrayList;
 
public class ArrayList_size 
{
	public static void main(String[] args) {
 
 
	ArrayList<String> list=new ArrayList<String>();
 
 
	//Adding element into Arraylist
 
		list.add("Bhavesh");
 
		list.add("Abhi");
 
		list.add("vivek");
 
		list.add("milan");
 
		System.out.println("Size of Arraylist: "+ list.size());
 
		//Retrieving Array list Element
		for (String s : list)
		{
 
			System.out.println(s); 
		}
 
	}
}

Output:

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Size of Arraylist: 4
Bhavesh
Abhi
vivek
milan

21. E set(int index, E element)

21. E set(int index, E element)
Replaces the element at the specified position in this list with the specified element.

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package com.spy.arraylist.method;
 
import java.util.ArrayList;
 
public class SetMethod 
{
 
	public static void main(String[] args) 
	{
 
		ArrayList<String> list=new ArrayList<>();
 
		list.add("Vivek");
		list.add("milan");
		list.add("Abhishek");
 
		for (String s : list) 
		{
			System.out.println(s);
		}
 
        // Replacing or Updating element at index 0	
 
		list.set(0,"Bhavesh");
 
 
		System.out.println("After Replacing element at index 0");
 
		for (String s : list) 
		{
			System.out.println(s);
		}
 
	}
 
}

Output:

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Vivek
milan
Abhishek
After Replacing element at index 0
Bhavesh
milan
Abhishek