Vector addAll() Method in Java
In Java, the addAll() method is used to add all elements from a specified Collection to the current Vector. The addAll() method allows you to efficiently append multiple elements to a vector in one operation.
Implementation:
// Java Program to addAll elements
// From Vector to Vector
import java.util.*;
class GFG
{
public static void main (String[] args)
{
// Created Vector
Vector<Integer> v = new Vector<Integer>();
// Created Second Vector
Vector<Integer> a = new Vector<Integer>();
a.add(1);
a.add(2);
a.add(3);
// Add all elements of Vector a to Vector v
v.addAll(a);
System.out.println("Vector : " + v);
}
}
Output
Vector : [1, 2, 3]
Now there are two versions of Vector addAll() method i.e one with the specified index and one without any index.
1. java.util.Vector.addAll(Collection C):
This method is used to append all of the elements from the collection passed as a parameter to this function to the end of a vector keeping in mind the order of return by the collection's iterator.
Syntax:
boolean addAll(Collection C)
Parameters: The method accepts a mandatory parameter C which is a collection of ArrayList. It is the collection whose elements are needed to be appended at the end of the vector.
Return Value: The method returns True if at least one action of append is performed, else False.
Below program illustrate the Java.util.Vector.addAll() method:
// Java code to illustrate boolean addAll()
import java.util.*;
import java.util.ArrayList;
public class GFG
{
public static void main(String args[])
{
// Creating an empty Vector
Vector<String> v = new Vector<String>();
// Use add() method to add elements in the Vector
v.add("Geeks");
v.add("for");
v.add("Geeks");
// A collection is created
Collection<String> c = new ArrayList<String>();
c.add("A");
c.add("Computer");
c.add("Portal");
c.add("for");
c.add("Geeks");
// Displaying the Vector
System.out.println("The vector is: " + v);
// Appending the collection to the vector
v.addAll(c);
// Clearing the vector using clear() and displaying
System.out.println("The new vector is: " + v);
}
}
Output
The vector is: [Geeks, for, Geeks] The new vector is: [Geeks, for, Geeks, A, Computer, Portal, for, Geeks]
2. java.util.Vector.addAll(int index, Collection C):
This method is used to append all of the elements from the collection passed as a parameter to this function at a specific index or position of a vector.
Syntax:
boolean addAll(int index, Collection C)
Parameters: This function accepts two parameters as shown in the above syntax and are described below.
- index: This parameter is of integer datatype and specifies the position in the vector starting from where the elements from the container will be inserted.
- C: It is a collection of ArrayList. It is the collection whose elements are needed to be appended.
Example:
// Java Program to addAll elements
// From Vector to Vector
import java.util.*;
class GFG
{
public static void main (String[] args)
{
// Created Vector
Vector<Integer> v = new Vector<Integer>();
v.add(1);
v.add(4);
// Created Second Vector
Vector<Integer> a = new Vector<Integer>();
a.add(2);
a.add(3);
int index=1;
// Add all elements of Vector a to Vector v
// at index 1
v.addAll(index,a);
System.out.println("Vector : " + v);
}
}
Output
Vector : [1, 2, 3, 4]
