ref C # pass in and out in the end is what doubts papers

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Today while browsing Bowen, see this article: C # ref pass in and out in the end what is? Use questions at the time of transfer target ref

Attached words:

This article was written in the morning, you want to publish in that moment, by the company off the net, the original modified part is missing.
Network is a day off, now home only then release it.

Have we all know, is to pass a reference type on the address, the type of value passed is the value, but also so many people are still confused, although circulated on the Internet a lot of related articles ref, everyone did not seem to take off his confusion.

I was recently looking at CYQ.Data framework of time talking about, since class is a reference to an address, the address itself is the pass, you have to write code to do ref transfer;

The original previously understand, been fooled do not understand what changed, he thought he was the original code was wrong.

When doubts today to help people, and only then their confusion to understanding.

Here I put the code on the articles of the original problem of small changes a bit

Posted do Example:

   /// <Summary> /// by passing fall http://cyq1162.cnblogs.com /// </ Summary> class Program     { static void the Main ( String [] args)         {            the Person P = new new the Person ( " John Doe " );            Change (the p-);            the Write (p.Name); // output is not Joe Smith John Doe            Change (the p-, " John Doe " );            the Write (p.Name); // output is John Doe           Change ( REF P);           the Write (p.Name);








// output is Wangwu
          the Console.ReadKey ();
    }
         static void Change (the Person P)         {            P = new new the Person ( " John Doe " );         } static void Change (the Person P, String name)         {             p.Name = name ;         } static void Change ( REF the Person P)         {             P = new new the Person ( " Wang Wu " );         }     }

Screenshot let everyone look at the way here is how the debugging and doubts.

F5 to run:

1: We run to the first line of code, breakpoints:

Highlights: the p-Address: 0x044becf8

2: We run to (p) of the Internal Change

Highlights: p address changes: 0x044becd0

Simply put: you p and p outside of this inside are not the same, it will not affect addresses outside of p.
Remark p value changed, it is not performed due to a breakpoint instantiated at a first line of code, so the values are the same.

Thus the first row in the result output: Zhang

3: run next to Change (p, "John Doe") internal function

Highlights: here inside the p address or changed into a 0x044becd0
but it points to the value is the same, so you put the value changed, so "John Doe" came out.
Note: internal and outside p p although not the same, but the point is the same value .

Thus the first row in the result output: John Doe

4: Finally Change (ref p) internal function

Highlights: Here p address internal and external p address is the same, no change .
Then redirected to a new object, but the value of the object's address has changed.
Note: the external address p = p internal address, which points to the values are values of the new object.

The third row then outputs the result: Zhang

The end result is as follows:

Last knot words:

For Class type using ref, in order to maintain the same address is referenced.
So, do not realize the type of reference only pass the address of a value type by value on the matter, to be honestly noted that, when the type of pass-by-reference, inside pass participants generate a new address.
So when we passed class reference, I prefer to use the new in-house migrant workers have to pay attention to pay attention.

The problem here seems to pass parameters field, but attached a ref.

Reproduced in: https: //my.oschina.net/secyaher/blog/274342

ref C # pass in and out in the end is what doubts papers

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