Declaring variable inside If

Question

Hi I did many times but not able to declare variable in side my IF-ELSE. Please tell me where I am making a mistake.

Shweta Lodha · Answer

Hello Graeme Pariot As per .Net you can not declare variable inside IF condition. That's the reason you are facing an error. To get rid of this error please declare your variable outside IF and then use that inside IF condition. That will work. Bit more info: Reason behind this is that IF expects an expression not a statement. If you wanna know more check this link: http://msdn.microsoft.com/en-us/library/aa664742(v=vs.71).aspx

Vulpes · Answer

It depends whether you're talking about declaring variables inside the condition or the body of the 'if' statement. If you're talking about the condition  then you simply can't do it as Shweta said. However you CAN declare variables in the body of an 'if' statement. The only restriction is that they must not have the same name as local variables declared in an 'outer' scope because there would be no way to access the latter if this were allowed. So this program compiles and works fine: using System; class Program { static void Main() { int i = 0 j = 0; if (i == 0) { // this compiles and works fine int k = 1; Console.WriteLine(k); Console.WriteLine(j); } /* if (i != 1) { // this doesn't compile because the 'outer' j // would no longer be accessible int j = 1; Console.WriteLine(); } */ Console.ReadKey(); } } However if you uncomment the second 'if' statement then it won't compile because the 'j' which is local to the 'if' statement would conflict with the 'j' which is local to the method as a whole.

Vulpes · Answer

No but the first correct answer (i.e. Shweta's) should be given the accolade which is what you've done :) As a correct answer had already been posted I only posted myself to add something which I thought might be of interest to you or other members reading the thread.

Graeme Pariot · Answer

Is there a way to mark two posts as answered ?