HashMap with objects

[otoro_java]

Hi,

Trying to learn HashMap and have lots of questions, so please excuse my ignorance.

I have two classes:
HashMapDemo.class
Account.class

Program is to do simple arithmetic, and write/read from file later on.

So far this is what I have:

Code:

//Account class

public class Account{
	
		String customerAccount;
		String customerName;
		double customerBalance;

	public Account(String customerAccount, String customerName,double customerBalance){ //Constructor
		this.customerAccount = customerAccount;
		this.customerName = customerName;	
		this.customerBalance = customerBalance;
	}
	
	public String toString() {
       
String output = customerAccount + " " +  customerName + " " + customerBalance;
		 
		 return output;
	}

    
	public double doDeposit(double newDeposit){
        //Purpose is to get the existing customer balance and add the new amount through input from joptionpane
		Double output = customerBalance + newDeposit;
		
		return output;
	}

Code:

//HashMapDemo class

import java.util.*;

public class HashMapDemo {
	
	int accountBalance = 100;
	
  public static void main(String[] args) {

    HashMap hm = new HashMap();
    
	Account anAcct1 = new Account("12-12-12", "Joe", 600);
	Account anAcct2 = new Account("45-45-45", "Jane", 500);

        //Account methods 
        Account methodAccount = new Account();
	

	hm.put("100", anAcct1);
	hm.put("200", anAcct2);
	
     System.out.println("Account number : " + hm);  
     
     System.out.println("\nMake a new dposit to account");

     //This is where I am stuck
     System.out.println(hm.get("100")+methodAccount.doDeposit(300)); 

     // Function toString()
     System.out.println("Account number : " + hm);

  }
}

Thanks in advance

[roots]

println method sees your "trouble code" as Object concatenated with double. You either need to force println to take all as string by,

Code:

System.out.println(""+hm.get("100")+methodAccount.doDeposit(300));

Or use Object.toString() method by

Code:

System.out.println(hm.get("100").toString()+methodAccount.doDeposit(300));

One more thing .. you do have default constructor for Account class ..

[JAdmin]

As roots pointed out, HashMap stores everything as objects. So when you retrieve an object from HashMap, you need to cast it to the actual type.