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some queries in the program

Venkat Ramsimha
Ranch Hand

Joined: Dec 28, 2004
Posts: 127
hi all,
consider the following program:
import java.util.*;
public class VecNum
public static void main(String argv[])
Vector v = new Vector();
v.add(new Integer(1));
v.add(new Integer(2));
for(int i=0; i < v.size();i ++)//line1
Integer iw =(Integer) v.get(i);//line2



In the above program i have some queries:
1.why we need to use vector for wrapping all the integer values
2.what is the purpose of using line1,line2,line3
3.when i compile this program its generating errors

Rob Harris

Joined: Nov 11, 2004
Posts: 10

1. You're not using a Vector to wrap your integer values, you're using the Integer Wrapper class. This turns your int primitives into Objects so they can be added to the collection.

2. Lines 1, 2 and 3 retrieve the Integer objects from the Vector. Vector.size() returns the number of components in the Vector and get() retrieves the objects using their index (just like an array).

3. The code compiles and runs fine for me.

Hope this helps!

SCJP 1.4
I agree. Here's the link:
subject: some queries in the program
jQuery in Action, 3rd edition