Java Programming - Objects and Collections - Discussion

The java.util.ArrayList.get(int index) method returns the element at the specified position in this list.

Following is the declaration for java.util.ArrayList.get() method

public E get(int index)

For example:

import java.util.ArrayList;

public class ArrayListDemo {
public static void main(String[] args) {

// create an empty array list with an initial capacity
ArrayList<Integer> arrlist = new ArrayList<Integer>(5);

// use add() method to add elements in the list
arrlist.add(15);
arrlist.add(22);
arrlist.add(30);
arrlist.add(40);
System.out.println(arrlist);

// let us print all the elements available in list
for (Integer number : arrlist) {
System.out.println("Number = " + number);
}

// retrieves element at 4th postion
int retval=arrlist.get(3);
System.out.println("Retrieved element is = " + retval);
}
}

Output:

[15, 22, 30, 40].
Number = 1.
Number = 22.
Number = 30.
Number = 40.
Retrieved element is = 40.

Methods are not synchronized?

But vector has synchronized, then how to it not synchronized?

@Jagan.

Yes, java.util.List is an interface and it is a subtype of the java.util.Collection interface.

The current code will not compile due to the error introduced due to incorrect paranthesis.

The correct code would be,
java.io.PrintWriter out = new java.io.PrintWriter(new java.io.OutputStreamWriter(System.out), true);

PrintWriter accepts OutputStream and boolean as its arguments in one its constructor. The above code will ensure that the PrintWriter obj acts as System.out

What about java.util.list, I think its correct but I think its interface. I have doubt over here please can u solve it for me ?