Using a variable name used in a child scope [duplicate]

Answer 1

Something I noticed that was not noted here. This will compile:

for (int i = 0; i < 10; i++)
{
    int a = i * 2;
}
for (int i = 0; i < 5; i++)
{
    int b = i * 2;
}

Taken together, these design decisions seem inconsistent, or at least oddly restrictive and permissive, respectively.

Answer 2

to all probability, any variable created in any of the child scope, will be put on the stackframe the moment method is entered.

This way, a similar name in a child scope can not co-exist with a variable name in another child scope.

They could have worked around this of course if they wanted, so I guess it ultimately has to do with design as well.. this way there is less chance for error

Answer 3

It is a design choice made by the designers of C#. It reduces potential ambiguity.

You can use it in one of the two places, inside the if or outside, but you can only define it in one place. Otherwise, you get a compiler error, as you found.

Answer 4

As Adam Crossland said, it's a design choice - Made to make sure you (or more likely, your fellow developers) dont misunderstand the code.

You often see private instance members prefixed with a "m_" or "_" (eg. _myVar or m_myVar) to avoid confusion..