c# Conditional object declaration

Question

I want to declare an object based on a variable value.

This is the code that I'm trying to run and that doesn't compiles:

if (bcheck == 0)
    IWebDriver driver = new ChromeDriver();
else if (bcheck == 1)
    IWebDriver driver = new FirefoxDriver();
else if (bcheck == 2)
    IWebDriver driver = new InternetExplorerDriver();

If I try to compile the code, I get this error message:

Embedded statement cannot be a declaration or labeled statement

How can I rewrite the code?

The driver object is used in the code below and I have to keep that name in order to don't change program flow.

Declare `driver` beforehand (with no value) and assign to it in each conditional. — Ry-, Jan 08 '18 at 08:59
I'd use a `Dictionary`, Similar https://stackoverflow.com/a/42505360/2946329 — Salah Akbari, Jan 08 '18 at 08:59
Ironically none of the answers explain the actual error being given, which is a lack of curly braces. — Rotem, Jan 08 '18 at 09:03
The `if`-statement is a block construct which defines a scope, a scope of a variable determines its visibility to the rest of a program. So if you don't declare the variable before the `if`-statement, you cannot access it outside. The error message itself is misleading because it tells you that you should use `{}` inside the `if` instead of the embedded statement(one liner) if you want to use a declaration. But if you would do that you still wouldn't be able to access the variable outside of the `if` as mentioned above. — Tim Schmelter, Jan 08 '18 at 09:06

score 3 · Answer 1 · edited Jan 08 '18 at 09:05

3

IWebDriver driver = null;
if (bcheck == 0)
    driver = new ChromeDriver();
else if (bcheck == 1)
    driver = new FirefoxDriver();
else if (bcheck == 2)
    driver = new InternetExplorerDriver();

Declare IWebDriver outside the if condition and assignment inside the if condition.

edited Jan 08 '18 at 09:05

Patrick Hofman

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answered Jan 08 '18 at 09:00

Yogesh Patel

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I generally don't initialize with `null`, since you might not find edge cases where the variable doesn't get set. – Patrick Hofman Jan 08 '18 at 09:05

score 2 · Answer 2 · answered Jan 08 '18 at 09:00

2

You must declare a single variable :

IWebDriver driver = null;
if (bcheck == 0)
   driver = new ChromeDriver();
else if (bcheck == 1)
   driver = new FirefoxDriver();
else if (bcheck == 2)
   driver = new InternetExplorerDriver();

answered Jan 08 '18 at 09:00

PMerlet

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I generally don't initialize with `null`, since you might not find edge cases where the variable doesn't get set. – Patrick Hofman Jan 08 '18 at 09:05

score 2 · Accepted Answer · answered Jan 08 '18 at 09:09

Don't use if / else, a dictionary is much simpler and more extensible.

var dictionary = new Dictionary<int, IWebDriver>
{
    [0] = new ChromeDriver(),
    [1] = new FirefoxDriver(),
    [2] = new InternetExplorerDriver()
};

var driver = dictionary[bcheck];

score 1 · Answer 4 · answered Jan 08 '18 at 09:00

1

You can declare driver before the if-else statement, but only iniitalize it inside the relevant condition:

IWebDriver driver = null;
if (bcheck == 0)
    driver = new ChromeDriver();
else if (bcheck == 1)
    driver = new FirefoxDriver();
else if (bcheck == 2)
    driver = new InternetExplorerDriver();

answered Jan 08 '18 at 09:00

Mureinik

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I generally don't initialize with `null`, since you might not find edge cases where the variable doesn't get set. – Patrick Hofman Jan 08 '18 at 09:04

c# Conditional object declaration

4 Answers4