C# 同时声明和分配多个字符串变量

Declare and assign multiple string variables at the same time

提问by Mathlight

I'm declaring some strings that are empty, so it won't throw errors later on.

我声明了一些空字符串，因此以后不会抛出错误。

I've read that this was the proper way:

我读过这是正确的方法：

string Camnr = Klantnr = Ordernr = Bonnr = Volgnr = Omschrijving = Startdatum = Bonprioriteit = Matsoort = Dikte = Draaibaarheid = Draaiomschrijving = Orderleverdatum = Regeltaakkode = Gebruiksvoorkeur = Regelcamprog = Regeltijd = Orderrelease = "";

But that doesn't work. I get this error: Klantnr does not exist in the current context.

但这不起作用。我收到此错误：Klantnr does not exist in the current context。

What did I do wrong?

我做错了什么？

采纳答案by Habib

You can do it like:

你可以这样做：

string Camnr, Klantnr, Ordernr, Bonnr, Volgnr;// and so on.
Camnr = Klantnr = Ordernr = Bonnr = Volgnr = string.Empty;

First you have to define the variables and then you can usethem.

首先，您必须定义变量，然后才能使用它们。

回答by Botz3000

You can to do it this way:

你可以这样做：

string Camnr = "", Klantnr = "", ... // or String.Empty

Or you could declare them all first and then in the next line use your way.

或者你可以先声明它们，然后在下一行使用你的方式。

回答by Carlos Landeras

Try with:

尝试：

 string Camnr, Klantnr, Ordernr, Bonnr, Volgnr, Omschrijving;
 Camnr = Klantnr = Ordernr = Bonnr = Volgnr = Omschrijving = string.Empty;

回答by sajanyamaha

Try

尝试

string     Camnr , Klantnr , Ordernr , Bonnr , Volgnr , Omschrijving , Startdatum ,    Bonprioriteit , Matsoort , Dikte , Draaibaarheid , Draaiomschrijving , Orderleverdatum , Regeltaakkode , Gebruiksvoorkeur , Regelcamprog , Regeltijd , Orderrelease ;

and then

进而

Camnr = Klantnr = Ordernr = Bonnr = Volgnr = Omschrijving = Startdatum = Bonprioriteit = Matsoort = Dikte = Draaibaarheid = Draaiomschrijving = Orderleverdatum = Regeltaakkode = Gebruiksvoorkeur = Regelcamprog = Regeltijd = Orderrelease = "";

回答by Kishore Kumar

string Camnr , Klantnr , Ordernr , Bonnr , Volgnr , Omschrijving , Startdatum , Bonprioriteit , Matsoort , Dikte , Draaibaarheid , Draaiomschrijving , Orderleverdatum , Regeltaakkode , Gebruiksvoorkeur , Regelcamprog , Regeltijd , Orderrelease;
Camnr = Klantnr = Ordernr = Bonnr = Volgnr = Omschrijving = Startdatum = Bonprioriteit = Matsoort = Dikte = Draaibaarheid = Draaiomschrijving = Orderleverdatum = Regeltaakkode = Gebruiksvoorkeur = Regelcamprog = Regeltijd = Orderrelease = string.Empty;

回答by HowlinWulf

An example of what I call Concatenated-declarations:

我称之为串联声明的一个例子：

string Camnr = "",
        Klantnr = "",
        Ordernr = "",
        Bonnr = "",
        Volgnr = "",
        Omschrijving = "",
        Startdatum = "",
        Bonprioriteit = "",
        Matsoort = "",
        Dikte = "",
        Draaibaarheid = "",
        Draaiomschrijving = "",
        Orderleverdatum = "",
        Regeltaakkode = "",
        Gebruiksvoorkeur = "",
        Regelcamprog = "",
        Regeltijd = "",
        Orderrelease = "";

Just my 2 cents, hope it helps someone somewhere.

只是我的 2 美分，希望它可以帮助某个地方的人。

回答by G .

Fairly old question but incase someone goes back.
This isn't as compact as the other answers above, but fairly readable and easier to type using Visual Studio Multi-Line selection shortcut [Alt+ Shift + ↑] (or other directions)

相当古老的问题，但以防万一有人回去。
这不像上面的其他答案那么紧凑，但使用 Visual Studio 多行选择快捷方式 [Alt+ Shift + ↑]（或其他方向）相当可读且更易于输入

string Camnr = string.Empty;
string Klantnr = string.Empty;

Type out all variable names on new lines. Multi-Select in front of them an type "string". Multi-Select behind them and type "= string.Empty;".

在新行中输入所有变量名称。多选他们前面的一个类型“字符串”。在它们后面多选并输入“= string.Empty;”。

回答by themefield

Just a reminder: Implicit type varin multiple declaration is not allowed.There might be the following compilation errors.

提醒一下：不允许在多个声明中使用隐式类型var。可能存在以下编译错误。

var Foo = 0, Bar = 0;

Implicitly-typed variables cannot have multiple declarators

隐式类型的变量不能有多个声明符

Similarly,

相似地，

var Foo, Bar;

Implicitly-typed variables must be initialized

必须初始化隐式类型的变量

回答by aac

string a = "", b = a , c = a, d = a, e = a, f =a;

string a = "", b = a , c = a, d = a, e = a, f =a;

回答by mklement0

^{All the information is in the existing answers, but I personally wished for a concise summary, so here's an attempt at it; the commands use intvariables for brevity, but they apply analogously to any type, including string.}

^{所有信息都在现有答案中，但我个人希望有一个简洁的总结，所以这里尝试一下；int为简洁起见，这些命令使用变量，但它们类似地适用于任何类型，包括string.}

To declare multiple variables and:

要声明多个变量和：

• either: initialize them each:

• 或者：初始化它们每个：

int i = 0, j = 1; // declare and initialize each; `var` is NOT supported as of C# 8.0

• or: initialize them all to the same value:

• 或：将它们全部初始化为相同的值：

int i, j;    // *declare* first (`var` is NOT supported)
i = j = 42;  // then *initialize* 

// Single-statement alternative that is perhaps visually less obvious:
// Initialize the first variable with the desired value, then use 
// the first variable to initialize the remaining ones.
int i = 42, j = i, k = i;

---

---

What doesn'twork:

什么不起作用：

• You cannot use varin the above statements, because varonly works with (a) a declaration that has an initialization value (from which the type can be inferred), and (b), as of C# 8.0, if that declaration is the onlyone in the statement (otherwise you'll get compilation error error CS0819: Implicitly-typed variables cannot have multiple declarators).

• Placing an initialization value only after the lastvariable in a multiple-declarations statement initializes the last variable only:

  int i, j = 1;// initializes *only* j

• 不能使用var在上面的语句，因为var只有（一）有一个初始化值（该类型可以推断）的声明，和（b）的作品，如C＃8.0中，如果该声明是唯一一个在语句（否则你会得到编译错误error CS0819: Implicitly-typed variables cannot have multiple declarators）。

• 配售后，才初始化值最后在多重声明语句变量初始化只有最后一个变量：

  int i, j = 1;// initializes *only* j