Question

I read this question(What is the scope of a lambda variable in C#?)

But it is about Lambda variable scope inside LINQ Query.

Now to my question

Lets say I have a very simple LINQ query.

var Foo = FoobBar.Select(x => x);
var x = somefunction();

Compiler says : A local variable 'x' cannot be declared in this scope because it would give a different meaning to 'x', which is already used in a 'child' scope to denote something else.

Why is that so? Shouldn’t Lambda variable cease to exist when LINQ query ends?

EDIT: After reading answers i came to conclusion that its the outside x (returned from function) whose scope extends inside LINQ Query.

Answer 1

It’s not about LINQ it’s about child scopes.

For example:

foreach (var bar in FooBar.Bars)
        {
            var x = FooBar.GetFoo();
        }
var x = new Foo();

produces exactly the same error message from compiler.

To fix that you just have to place variables in different (non-nesting) scopes. For example:

foreach (var bar in FooBar.Bars)
        {
            var x = FooBar.GetBar();
        }
{
    var x = new Foo();
}