underscores on variable names

[Peter Kirk]

Hi

I am looking at some C# code, and can see in some of the classes there are
instance variables whose names start with an underscore, for example:

private string _projectId;

Is there a reason for using underscores like this in C#?

Thanks,
Peter

[Cor Ligthert]

Peter,

Personal preference, the most I see used at the moment is camelCase or other
styles like that.

Cor

[Joanna Carter \(TeamB\)]

"Peter Kirk" <[e-mail]> a écrit dans le message de news:
uM************* @TK2MSFTNGP12.p hx.gbl...

I am looking at some C# code, and can see in some of the classes there are
instance variables whose names start with an underscore, for example:

private string _projectId;

Is there a reason for using underscores like this in C#?

Some folks use it as a prefix to distinguish a field from a property without
an underscore; Delphi programmers use a convention of prefixing fields with
'F', I have also seen ''m' used in C# (to denote memory I guess ?)

Joanna

--
Joanna Carter
Consultant Software Engineer

[Gunter Spranz]

Just google for "C# naming conventions" or "C# coding style guide", you'll
find lots of infos :-)

"Joanna Carter (TeamB)" <jo*****@nospam forme.com> schrieb im Newsbeitrag
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..

"Peter Kirk" <[e-mail]> a écrit dans le message de news:
uM************* @TK2MSFTNGP12.p hx.gbl...

I am looking at some C# code, and can see in some of the classes there
are
instance variables whose names start with an underscore, for example:

private string _projectId;

Is there a reason for using underscores like this in C#?

Some folks use it as a prefix to distinguish a field from a property
without
an underscore; Delphi programmers use a convention of prefixing fields
with
'F', I have also seen ''m' used in C# (to denote memory I guess ?)

Joanna

--
Joanna Carter
Consultant Software Engineer

[Bob Powell [MVP]]

Note that this practice isn't official because it isn't CLR compliant.

I use the following naming conventions in my code. Similar styles are used
by others;

Underbar denotes a field. Fields are ALWAYS protected or private. The name
is the same as the property name but has a preceeding underbar and a lower
case initial letter such as _myInteger

Property names use the name of the property backer variable witout the
underbar and with the initial capital letter such as MyInteger.

A property is structured so:

protected int _myInteger;

public int MyInteger
{
get{return _myInteger;}
set{_myinteger= value;}
}

All names are CamelCased

This prctice is particularly useful if you need to provide code in both C#
and VB as I do often because I can write in C# and convert to VB using a
conversion tool. If you don't use the underbar in this way VB, which is too
stupid to recognise the difference between lower-case and upper-case
characters, chokes on the names myInteger and MyInteger being the same.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/faqmain.htm

All new articles provide code in C# and VB.NET.
Subscribe to the RSS feeds provided and never miss a new article.

"Peter Kirk" <[e-mail]> wrote in message
news:uM******** *****@TK2MSFTNG P12.phx.gbl...

Hi

I am looking at some C# code, and can see in some of the classes there are
instance variables whose names start with an underscore, for example:

private string _projectId;

Is there a reason for using underscores like this in C#?

Thanks,
Peter

[Dennis Myrén]

I use the underscore, not to distinguish a field from a property,
but to "underscore " that this is a private member.
Some use "m" or "m_" but they all use it to say that this is a private field
member.
And some of us does'nt use this notation at all, but rather use "this"
keyword or nothing at all.

This is partly to make it easier to read, and partly to distinguish local
variables
from private members, which would otherwise potentially have the same name.
class A
{
private int value;
/* Sets the private member to the value specified. */
void SetValue ( int value )
{
// Would not work since we are assigning the parameter variable.
value = value;
// OK. This is a way to distuingish a local variable
// and a private member variable that have the same name.
this.value = value;
// OK (assuming the private member "value" was renamed "_value").
// If we always use some special character as a prefix on private
members,
// we will never have this "issue".
_value = value;
}
}

--
Regards,
Dennis JD Myrén
Oslo Kodebureau
"Joanna Carter (TeamB)" <jo*****@nospam forme.com> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..

"Peter Kirk" <[e-mail]> a écrit dans le message de news:
uM************* @TK2MSFTNGP12.p hx.gbl...

I am looking at some C# code, and can see in some of the classes there
are
instance variables whose names start with an underscore, for example:

private string _projectId;

Is there a reason for using underscores like this in C#?

Some folks use it as a prefix to distinguish a field from a property
without
an underscore; Delphi programmers use a convention of prefixing fields
with
'F', I have also seen ''m' used in C# (to denote memory I guess ?)

Joanna

--
Joanna Carter
Consultant Software Engineer

[Bob Powell [MVP]]

The m prefix is a holdover from the days of MFC when the prefix m denoted a
member variable to distinguich them from local variables.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

Answer those GDI+ questions with the GDI+ FAQ
http://www.bobpowell.net/faqmain.htm

All new articles provide code in C# and VB.NET.
Subscribe to the RSS feeds provided and never miss a new article.

"Joanna Carter (TeamB)" <jo*****@nospam forme.com> wrote in message
news:%2******** ********@TK2MSF TNGP10.phx.gbl. ..

"Peter Kirk" <[e-mail]> a écrit dans le message de news:
uM************* @TK2MSFTNGP12.p hx.gbl...

I am looking at some C# code, and can see in some of the classes there
are
instance variables whose names start with an underscore, for example:

private string _projectId;

Is there a reason for using underscores like this in C#?

Some folks use it as a prefix to distinguish a field from a property
without
an underscore; Delphi programmers use a convention of prefixing fields
with
'F', I have also seen ''m' used in C# (to denote memory I guess ?)

Joanna

--
Joanna Carter
Consultant Software Engineer

[Daniel O'Connell [C# MVP]]

> Some folks use it as a prefix to distinguish a field from a property

without
an underscore; Delphi programmers use a convention of prefixing fields
with
'F', I have also seen ''m' used in C# (to denote memory I guess ?)

"module" actually, if memory serves. It would be an example of scope
specification in a hungarian variable name: m_lpzstrName = module field that
is a long(I *think*) pointer to a null terminated string. I don't recall for
sure what the l meant in lp.

Anyway, the common prefixes I can recall are
p for parameter,
m for module,
g for global,

probably others I don't know.

[Daniel O'Connell [C# MVP]]

"Daniel O'Connell [C# MVP]" <[e-mail]> wrote in
message news:e%******** *******@TK2MSFT NGP15.phx.gbl.. .

Some folks use it as a prefix to distinguish a field from a property
without
an underscore; Delphi programmers use a convention of prefixing fields
with
'F', I have also seen ''m' used in C# (to denote memory I guess ?)

"module" actually, if memory serves. It would be an example of scope

Err, member. Thanks Bob.

[Cor Ligthert]

Bob,

I was making my message to you in this thread before I saw this one.

:-)

Sorry

Cor