Java ArrayList.add(int index, E element) Method

public void add(int index, E element)

This method is used to insert an element to the ArrayList object at a specified index.

Package: java.util

Java Platform : Java SE 8

Syntax:

add(int index, E element)

Parameters:

Return Value:
This method does not return any value.

Throws:
IndexOutOfBoundsException - if the index is out of range (index < 0 || index > size())

Pictorial presentation of ArrayList.add() Method

Example: ArrayList.add(int index, E element) Method

The following example creates an ArrayList with a capacity of 7 elements. Using the above method we have inserted two elements in 2nd and 4th position.

import java.util.*;

public class test {
   public static void main(String[] args) {
      
    // create an empty array list with an initial capacity
    ArrayList<String> color_list = new ArrayList<String>(7);

    // use add() method to add values in the list
    color_list.add("White");
    color_list.add("Black");
    color_list.add("Red");
    color_list.add("White");
	color_list.add("Yellow");
	    
	// Insert Nocolor in 2nd and 4th position in the list 	
	color_list.add(1,"Nocolor");	
	color_list.add(3,"Nocolor");		
		
	// Print out the colors in the ArrayList
    for (int i = 0; i < 7; i++)
      {
         System.out.println(color_list.get(i).toString());
      }
  }
} 
  

Output:

F:\java>javac test.java

F:\java>java test
White
Nocolor
Black
Nocolor
Red
White
Yellow

Example of Throws: add(int index, E element) Method

IndexOutOfBoundsException - if the index is out of range (index < 0 || index > size()).

Let

int index = set(-8);

in the above example.

Output:

White                                                  
Nocolor                                                
Black                                                  
Nocolor                                                
Red                                                    
White                                                  
Yellow                                                 
Exception in thread "main" java.lang.IndexOutOfBoundsEx
ception: Index: 7, Size: 7                             
        at java.util.ArrayList.rangeCheck(ArrayList.jav
a:635)                                                 
        at java.util.ArrayList.get(ArrayList.java:411) 
        at test.main(test.java:23) 

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