Convert ArrayList to Vector in Java
There are several ways to convert ArrayList to Vector. We can use a vector constructor for converting ArrayList to vector. We can read ArrayList elements one by one and add them in vector.
Approach 1: (Using Vector Constructor)
- Create an ArrayList.
- Add elements in ArrayList.
- Create a vector and pass the ArrayList in Vector Constructor.
Vector(Collection c): Creates a vector that contains the elements of collection c.
Vector<E> v = new Vector<E>(Collection c);
Example:
Java
// Java program to Convert ArrayList to Vector import java.util.ArrayList; import java.util.Vector; public class GFG { public static void main(String[] args) { // create ArrayList ArrayList<Integer> ArrList = new ArrayList<Integer>(); // add elements in ArrayList ArrList.add( 10 ); ArrList.add( 20 ); ArrList.add( 30 ); ArrList.add( 40 ); ArrList.add( 50 ); // display ArrayList System.out.println( " ArrayList : " + ArrList); // create vector and pass the ArrayList in vector // constructor Vector<Integer> vector = new Vector<Integer>(ArrList); // print vector System.out.println( " Vector : " + vector); } } |
ArrayList : [10, 20, 30, 40, 50] Vector : [10, 20, 30, 40, 50]
Approach 2: (Using for loop)
- Create a ArrayList.
- Add some values in ArrayList.
- Create an Vector.
- Execute a loop.
- Traverse each element of ArrayList from the left side to the right side.
- Add the ArrayList elements in Vector.
Example:
Java
// Java program to Convert ArrayList to Vector import java.util.Vector; import java.util.ArrayList; public class GFG { public static void main(String[] args) { // Create a ArrayList that contain strings ArrayList<String> Arrlist = new ArrayList<String>(); // add values in ArrayList Arrlist.add( "A" ); Arrlist.add( "B" ); Arrlist.add( "C" ); Arrlist.add( "D" ); Arrlist.add( "E" ); // Display the ArrayList System.out.println( " ArrayList : " + Arrlist); // create a vector Vector<String> v = new Vector<String>(); // Convert ArrayList to Vector // get the size to ArrayList int n = Arrlist.size(); // execute for loop from 0 to n for ( int i = 0 ; i < n; i++) { // get the elements from ArrayList // and add the arrayList elements in vector v.add(Arrlist.get(i)); } // Display Vector System.out.println( "\n vector : " + v); } } |
ArrayList : [A, B, C, D, E] vector : [A, B, C, D, E]
Approach 3: (Using addAll() method)
This method is used to append all 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.
Example:
Java
// Java program to Convert ArrayList to Vector import java.io.*; import java.util.*; class GFG { public static void main(String[] args) { ArrayList<String> listStrings = new ArrayList<>(); listStrings.add( "Beginner" ); listStrings.add( "for" ); listStrings.add( "Beginner" ); // create empty vector object Vector<String> vStrings = new Vector<>(); // use the addAll method vStrings.addAll(listStrings); System.out.println( "Vector contains: " + vStrings); } } |
Vector contains: [Beginner, for, Beginner]
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