How to update value in dictionary if second parameter of it is list of objects C#

Question

How can I change value in dictionary if my second parameter is list of objects?

I have this model:

public class Account
{
    public string AccountType { get; set; }
    public string AccountName { get; set; }
    public BigInteger AccountNumber { get; set; }
    public decimal Balance { get; set; }
    public decimal AvailableBalance { get; set; }
    public string Currency { get; set; }
    public decimal InterestRate { get; set; }
}

I've made a dictionary where key is string and value is List of objects type of Account:

Dictionary<string, List<Account>> dictionaries = new Dictionary<string, List<Account>>();

I've filed list of accounts with some custom data:

List<Account> NMoAccounts = new List<Account>(){
                            new Account {AccountName="Credit card 1", AccountNumber=5234567890, AccountType="Credit card", AvailableBalance=234.4m, Balance=432.64m, Currency="euro", InterestRate=1.5m},
                            new Account {AccountName="Credit card 3", AccountNumber=1357924680, AccountType="Credit card", AvailableBalance=24.06m, Balance=-32.123m, Currency="euro", InterestRate=1.5m},
                            new Account {AccountName="Current card 10", AccountNumber=4567890123, AccountType="Current card", AvailableBalance=1.8m, Balance=2.3m, Currency="euro", InterestRate=1.5m},
                            new Account {AccountName="Credit card 5", AccountNumber=857624621, AccountType="Credit card", AvailableBalance=31.4m, Balance=-132.123m, Currency="euro", InterestRate=1.5m} 
                        };

dictionaries.Add("user", NMoAccounts);

I would like to do something like this:

1. Get directory by key.
2. Find for example Account that has two account numbers(values of account number are passed by client): for example 5234567890 and 1357924680 inside of that dictionary.
3. Decrease Balance from account with number 5234567890 for 5(this value is also passed by client) and increase balance on account with number 1357924680 for 5.

Something like I'm simulating money transaction between bank accounts.

Can I do this operation with dictionary? If someone has some tutorial with similar subject I would be more than thankful.

Answer 1

It is quite straight forward:

// find list in dictionary
List<Account> acctList = dictionaries[keyString];
// search account in list
Acount account = acctList.FirstOrDefault(a => a.AccountName = acctName);
if(account == null) // some error handling here
// modify account
accout.Balance -= 5;

Because the dictionary stores references and also the list contains references, you can modify these objects directly.