about toString method

How to make use of toString method to convert object to string,an object which is passed as an argument to the toString method.
For example:
String s=toString(e)
e is an employee class object.

I don't think I understand your question. Which toString method you are speaking about and What do you mean by "make use of toString method" ?

package pack;
import java.util.*;
import java.io.*;
public class Samp {
public static void main(String args[]) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int n = 0;
try {
System.out.print("Enter the Number of records :");
n = Integer.parseInt(br.readLine());
ArrayList al = new ArrayList();
Employee e = null;
for (int i = 0; i < n; i++) {
System.out.print("Enter the Name:");
String name = br.readLine();
System.out.print("Enter the Age:");
int age = Integer.parseInt(br.readLine());
System.out.print("Enter the Designation:");
String desig = br.readLine();
e = new Employee(name, age, desig);
al.add(i, e);
}
// String s=al.toString(e);
// System.out.println(s);
Iterator i = al.iterator();
while (i.hasNext()) {
System.out.println((i.next()));
}
} catch (Exception e) {
System.out.println("Invalid Input");
}
}
}
class Employee
{
String name, desig;
int age;
public Employee()
{
}
public Employee(String name, int age, String desig)
{
this.name = name;
this.age = age;
this.desig = desig;
}
public String toString(Object e)
{
return e;
}
}
this is my prog and i want the output in string format(presently m getting as classname@memory address

At the bottom of your program I see this:

This will not compile. The method must return a String but you are trying to return an Object - the compiler will give an error message about that.

So please post the correct code, and please use code tags when you post code, so that the forum can display your code properly.

package pack;
import java.util.*;
import java.io.*;
public class Samp {
public static void main(String args[]) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int n = 0;
try {
System.out.print("Enter the Number of records :");
n = Integer.parseInt(br.readLine());
ArrayList al = new ArrayList();
Employee e = null;
for (int i = 0; i < n; i++) {
System.out.print("Enter the Name:");
String name = br.readLine();
System.out.print("Enter the Age:");
int age = Integer.parseInt(br.readLine());
System.out.print("Enter the Designation:");
String desig = br.readLine();
e = new Employee(name, age, desig);
al.add(i, e);
}
// String s=al.toString(e);
// System.out.println(s);
Iterator i = al.iterator();
while (i.hasNext()) {
System.out.println((i.next()));
}
} catch (Exception e) {
System.out.println("Invalid Input");
}
}
}
class Employee
{
String name, desig;
int age;
public Employee()
{
}
public Employee(String name, int age, String desig)
{
this.name = name;
this.age = age;
this.desig = desig;
}
}
this is the exact code i wrote and i want to know the exact implementation of toString method

The exact implementation depends on what you want it to do. For example you could return just the name
or it could return the name with the age in brackets afterwards

Basically, it's completely up to you what it does.

[Kranthi Kondapaka:] exact implementation of toString method

/**
 * The String class represents character strings. All
 * string literals in Java programs, such as "abc", are
 * implemented as instances of this class.
 * 
 * Strings are constant; their values cannot be changed after they
 * are created. String buffers support mutable strings.
 * Because String objects are immutable they can be shared. For example:
 * 
 *     String str = "abc";
 * 
 * is equivalent to:
 * 
 *     char data[] = {'a', 'b', 'c'};
 *     String str = new String(data);
 * 
 * Here are some more examples of how strings can be used:
 * 
 *     System.out.println("abc");
 *     String cde = "cde";
 *     System.out.println("abc" + cde);
 *     String c = "abc".substring(2,3);
 *     String d = cde.substring(1, 2);
 *
 * The String class includes methods for examining
 * individual characters of the sequence, for comparing strings, for
 * searching strings, for extracting substrings, and for creating a
 * copy of a string with all characters translated to uppercase or to
 * lowercase. 
 *
 * Unless otherwise noted, passing a null argument to a constructor
 * or method in this class will cause a {@link NullPointerException} to be
 * thrown.
 */

That's the String class.

For any Java Object, if one does not provide a toString() method: