Lab2 - OOP 
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- Create a class called Account.

- This class should contain the following instance variables:
  user_name : string
  account_no :  string 
  balance : decimal

- Create a constructor for Account class that would initialize the instance variables.

- Create public properties for the three instance variables.

- Create a method called Print that would print user_name, account_id and balance.

- Create a method called Deposit that would increase the balance according to the value deposited by the user, and return the updated balance.
  This method should call Print method so that the user would see his current balance

- Create a method called Withdraw that would deduct a certain amout of money,chosen by the user,  from his balance, and return the updated balance. 
  This method should call Print method so that the user would see his current balance

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- Create another class AccountTest that has a Main method

- Create two objects of class Account called account1 and account2 with the following details:
   account1 : user_name = ahmad, account_no 123, balance= 1500
   account2: user_name = ali , account_no= 456, balance= 500

- Write a proper code to perform the following actions:
  ahmad wishes to make a query about his balance
  ahmad wishes to withdraw 500 from his account
  ali wishes to deposit 300 in his account

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- Go back to class Account; modify the public property for "balance" so that it will only accept positive values.

- In class AccountTest,create a third object called account3 with the following initial values:
  user_name = enas, account_no=790 , balance= 1150.5 (Hint: add m after the number) 

-In class AccountTest,create another object called account4 with the following initial values:
 user_name = Sahar, account_no=780 , balance= -500.
 call print( ) using object account4.