Declare and assign multiple string variables at the same time

Question

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

I\'ve read that this was the proper way:

string Camnr = Klantnr = Ord         


        

Answer 1

Try with:

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

Answer 2

You can to do it this way:

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

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

Answer 3

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

var Foo = 0, Bar = 0;

Implicitly-typed variables cannot have multiple declarators

Similarly,

var Foo, Bar;

Implicitly-typed variables must be initialized

Answer 4

^{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 int variables for brevity, but they apply analogously to any type, including string.}

To declare multiple variables and:

• either: initialize them each:

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:

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;

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What doesn't work:

• You cannot use var in the above statements, because var only 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 only one 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 last variable in a multiple-declarations statement initializes the last variable only:

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