variable scope in statement blocks

Question

for (int i = 0; i < 10; i++)
{
    Foo();
}
int i = 10; // error, \'i\' already exists

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for (int i = 0; i < 10; i         


        

Answer 1

In the first example, the declaration of i outside of the loop makes i a local variable of the function. As a result, it is an error to have another variable name i declared within any block of that function.

The second, i is in scope only during the loop. Outside of the loop, i can no longer be accessed.

So you have seen the errors, but there is nothing wrong with doing this

for (int i = 0; i < 10; i++)
{
  // do something
}

foreach (Foo foo in foos)
{
   int i = 42;
   // do something 
}

Because the scope of i is limited within each block.