Share via

Compiler Error CS0135

  • Article

'declaration1' conflicts with the declaration 'declaration2'

The compiler does not allow hiding names, which commonly leads to logic errors in your code.

Example

The following sample generates CS0135:

// CS0135.cs
public class MyClass2
{
   public static int i = 0;

   public static void Main()
   {
      {
         int i = 4;
         i++;
      }
      i = 0;   // CS0135
   }
}

From the C# Language Specification, Section 7.5.2.1:

For each occurrence of a given identifier as a simple-name in an expression or declarator, within the local variable declaration space (§3.3) immediately enclosing that occurrence, every other occurrence of the same identifier as a simple-name in an expression or declarator must refer to the same entity. This rule ensures that the meaning of a name is always the same within a given block, switch block, for-, foreach- or using-statement, or anonymous function.