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Cannot Use Local Variable Before It Is Declared C#


Error, usage before declaration. He's eating it."); NewRoom2.Room2(); break; case false: Console.WriteLine("You can't give something you don't have."); goto decide; } break; That being said - I would recommend not nesting switch statements like this. The scope of i is therefore the entire Main() function, and that means that the use in the for loop is a re=use, and therefore is not allowed. The latter ‘i' does of course belong to the main block. http://homeshareware.com/cannot-use/cannot-use-local-variable-before-it-is-declared-c-net.html

I wouldn't really say "broken". Can I use that to take out what he owes me? In fact, it has saved myself and some others I know several times from screwing up the value of local variables by reusing them inside a loop. Why, the wind shear on a pink ball alone can take the head clean off a 90 pound midget at 300 yards. 02-01-2014 #8 phantomotap View Profile View Forum Posts Master http://stackoverflow.com/questions/222601/variable-declaration-in-a-c-sharp-switch-statement

Cannot Use Local Variable Before It Is Declared C#

I learnt something new just now :) thanks –Mahdi Tahsildari Dec 6 '12 at 4:47 add a comment| up vote 3 down vote The second code you showed is perfectly fine Unless you use brackets, the scope of a variable in a switch statement is the entire body of the switch statement. 2. asked 3 years ago viewed 4664 times active 3 years ago Related 13Is it possible to design a language that doesn't have syntax errors?0Why doesn't the DART language use a special C# takes great pains to promote readability by prohibiting some constructs of other languages that are confusing or or easily abused.

Declaring after a case guard is not. How to remove text field value after comma using apex code? The scope of a local variable is from the point where it's defined to the end of the block in which it's defined. C# Case Statement This is not true.

In general, you cannot have the same variable used in a nested scope and its parent's scope (with a few exceptions). Edited by Louis.fr Wednesday, March 07, 2012 1:31 PM Wednesday, March 07, 2012 1:30 PM Reply | Quote Microsoft is conducting an online survey to understand your opinion of the Msdn j will be uninitialized (have some random number), but the compiler compiles it. string x = "s"; // Illegal - cannot hide parameters.

I'm no C++ programmer, but in C: switch(val) { int x; case VAL: x=1; } Works fine. C# Dictionary So the order of the case blocks appears to be important here in a way that's not entirely obvious -- Normally I could write these in any order I wish, but But this seems like it's just bound to cause confusion. How to decline a postdoc interview if there is some possible future collaboration?

C# Switch Scope

Consider this example compiles on GCC 4.5.3 and Visual Studio 2008 (might be a compliance issue tho' so experts please weigh in) #include struct Foo{}; int main() { int i http://programmers.stackexchange.com/questions/195032/why-doesnt-c-have-local-scope-in-case-blocks This is the big day, with Visual Studio 2008 Reply Charlie Calvert's Community Blog says: December 10, 2007 at 3:09 am Welcome to the thirty-sixth issue of Community Convergence. Cannot Use Local Variable Before It Is Declared C# The C# Language Specification states the following: The scope of a local variable or constant declared in a switch block is the switch block. C# Switch Variable This is most clearly illustrated by Duff's device.

Why, the wind shear on a pink ball alone can take the head clean off a 90 pound midget at 300 yards. 01-31-2014 #7 Cat View Profile View Forum Posts Registered break; } share|improve this answer answered Sep 18 '08 at 13:16 Andrew Eidsness The variable can be declared, but it cannot be initialized. –Richard Corden Sep 18 '08 at This behavior is inteded to make incorrect re-use of variable names (such as in a cut and paste) less likely. [Author: Eric Gunnerson] Back totop Search this blog Search all blogs Can someone please help me fix it? C# Variable Scope

Tuesday, March 06, 2012 8:44 PM Reply | Quote 0 Sign in to vote Also something you can do is variables are defined for a scope. Tags Local Variable Scoping Variable redeclaration Comments (7) Cancel reply Name * Email * Website DotNetKicks.com says: November 9, 2007 at 1:52 pm You've been kicked (a good thing) - Trackback Is it possible for it not to do that? Check This Out share|improve this answer answered Aug 1 '11 at 21:38 Oscar Gomez 14.8k96399 add a comment| up vote 1 down vote You are only setting the value of sum for ONE condition

emp.ManagementInfo(); break; } case 3: { Student st = new Student(); st.EducationInfo(); break; } ... } share|improve this answer edited Dec 5 '12 at 13:49 answered Dec 5 '12 at 13:29 Could get around that by either adding postfix ++ to the to, or mentioning the use case is for memory mapped IO. But from C++ point of view, the problem is with case ANOTHER_VAL: label. –AnT Nov 7 '13 at 8:14 In C++, unlike in C, declarations are a subset of

Consider the following code: class C { void Foo() { int x; { // (1) // 2005 Compiler compiles this statement without errors. // 2008 Compiler yields CS0841: Cannot use variable

The most likely explanation: 1): You can't jump over declarations having assignments in C++.* (The scope from the `case' is different than the scope of the `switch'.) 2): You can't implicitly Why is this such a problem? share|improve this answer answered Sep 18 '08 at 17:02 Jeremy 1,47331622 Why would you do this? –Landon Sep 18 '08 at 17:05 Very nice. would initialize the variable, but here it simply declares it.

To get around it, do this: switch (val) { case VAL: { // This **will** work int newVal = 42; } break; case ANOTHER_VAL: ... What is not allowed is to have code in a case-branch that falls through. Essentially, you can shadow a class member within a class method, and you can shadow an outer class member within an inner class member, but most other cases of variable shadowing share|improve this answer answered Apr 15 '13 at 23:44 Guvante 60639 3 What about for (int i = 0; i < n; i++) Write(i); /* legal */ Write(i); /* illegal

Antonym for Nourish Query for highest version Why did Michael Corleone not forgive his brother Fredo? Can I cite email communication in my thesis/paper? All rights reserved. break; } Note that even though it is now valid from C point of view, it remains invalid from C++ point of view.

The original code is indeed invalid in both C and C++, but for completely different unrelated reasons. No, because the variable scope has ended right there. Of course, I only really ever tried C#2 for any real project so it also may have changed and I just didn't notice. [/Edit] I imagine this is born of C# Marked as answer by Thegluestickman Tuesday, March 06, 2012 8:44 PM Tuesday, March 06, 2012 7:40 PM Reply | Quote Moderator All replies 0 Sign in to vote You need to

Browse other questions tagged c# c++ scope switch-statement or ask your own question. I think the real thing that we should be concluding from this little exercise is that we should be choosing better names for our variables and fields! Otherwise we can simply go back to the C days, where we h 4 years ago Reply chris because you are declaring i twice in the same block of code ie However, you output an error saying that the second use (the function local) is a redefinition of i in the child scope.

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