What is difference between single and multiple declarations in one line?

Question

I would like to know the differences between these two ways of declaring variables.

Type 1

private string procedure_add = "";
private string procedure_update = "";
private string procedure_delete = "";

Type 2

private string procedure_add = "", procedure_update = "", procedure_delete = "";

Does this give the same effect?. Is the memory consumption the same?

I would like to suggest you use `string.Empty` instead of `""`. — Sergey Vyacheslavovich Brunov, Feb 02 '12 at 08:19
this should be explained in various books about programming. You can check out [the list of freely available books](http://stackoverflow.com/q/194812/238902) here on SO — default, Feb 02 '12 at 08:21
Thanks all. @Serge string.Empty and "" what is the different?. — Sagotharan, Feb 02 '12 at 08:24
@Serge: I'd suggest the use of whatever you prefer, as long as it's consistent. — diggingforfire, Feb 02 '12 at 08:29
@Sagotharan, here is the answer: [What is the difference between String.Empty and “”](http://stackoverflow.com/questions/151472/). Long story short, for readability reason. — Sergey Vyacheslavovich Brunov, Feb 02 '12 at 08:29
@Serge: Right, I find `""` to be more readable than `String.Empty` — diggingforfire, Feb 02 '12 at 08:42

Ravi Gadag · Accepted Answer · 2012-02-02T09:43:20.730

There is no any difference. it's all about the accessibility. the way how the code looks. suppose if you have 10000+ line of code, while editing you may get stumped by identifying the "," in declaration .

if you have one or two variable, then declare it in a single line
writing each declaration in separate line will look code cleaner, and better to debug.

this method which i prefer to use.

private string yourVar = String.Empty;

score 1 · Answer 2 · answered Feb 02 '12 at 08:15

There is no any difference. Just coding style.

EDIT

As @Aphelion mantioned in first case you can modify accessibility. From the code generation point of view the both version produce exactly the same IL

MyClass..ctor:
IL_0000:  ldarg.0     
IL_0001:  ldstr       ""
IL_0006:  stfld       UserQuery+MyClass.procedure_add
IL_000B:  ldarg.0     
IL_000C:  ldstr       ""
IL_0011:  stfld       UserQuery+MyClass.procedure_update
IL_0016:  ldarg.0     
IL_0017:  ldstr       ""
IL_001C:  stfld       UserQuery+MyClass.procedure_delete
IL_0021:  ldarg.0     
IL_0022:  call        System.Object..ctor
IL_0027:  ret

Exactly. However using single lines you can modify the accessibility. — Myrtle, Feb 02 '12 at 08:16

score 0 · Answer 3 · answered Feb 02 '12 at 08:16

0

There is no difference, the one is just a short-hand.

answered Feb 02 '12 at 08:16

janhartmann

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score 0 · Answer 4 · answered Feb 02 '12 at 08:16

0

I think no different, from my understanding second type is to minimize the line of code.

answered Feb 02 '12 at 08:16

Siti

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+1 Thanks for immediate answer. Expand your answer, it more helpful. – Sagotharan Feb 02 '12 at 09:00

score 0 · Answer 5 · answered Feb 02 '12 at 08:28

In addition to the overall "They are the same, but differ in readability" I would like to add 3 remarks:

In Visual Basic 6 (and earlier) Dim x , y as Integer would result in y being an Integer and x a Variant
In C int *ip, i; would result in ip being a pointer to an int and i to be an int.
In unsafe C# code int *ip, i; will result in ip being a pointer to int and i ALSO being a pointer to int.

What is difference between single and multiple declarations in one line?

5 Answers5

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