How to understand the reference types in C#? How to use it? Please give a vivid answer. .

I'll tell you how to understand the citation type. . For example.

Premise, you have a support account, bound with ID number, mobile phone number, your user name and email address.

Suppose:

1 ID number, mobile phone number, user name and email address can all be logged into your Alipay;

2 You have 10000 yuan in Alipay;

The transaction will not generate any handling fees, and there will be no other income such as interest.

at present

1 Log in with your ID number and deposit 5,000 yuan;

It costs 3000 yuan to log in with your mobile phone number;

3 login with your user name, it costs 8000 yuan;

Log in by email and deposit 2000 yuan.

Q: How much balance is in your Alipay?

A:10000+5000-3000-8000+2000 = 6000.

Ok, now let's talk about the quotation.

Now, your ID number, mobile phone number, user name and email address are all references to your Alipay account. No matter which way you log in, the transaction is for which account.