Edit

Compiler Error CS0201

  • Article

Only assignment, call, increment, decrement, and new object expressions can be used as a statement

The compiler generates an error when it encounters an invalid statement. An invalid statement is any line or series of lines ending in a semicolon that does not represent an assignment (=), method call (), new, -- or ++ operation. For more information, see Statements and Operators and expressions.

Example 1

The following sample generates CS0201 because 2 * 3 is an expression, not a statement. To make the code compile, try assigning the value of the expression to a variable.

// CS0201.cs  
public class MainClass  
{  
   public static void Main()  
   {  
      2 * 3;   // CS0201  
      // Try the following line instead.  
      //   int i = 2 * 3;  
   }  
}

Example 2

The following sample generates CS0201 because checked by itself is not a statement, even though it is parameterized by an increment operation.

// CS0201_b.cs  
// compile with: /target:library  
public class MyList<T>
{  
   public void Add(T x)  
   {  
      int i = 0;  
      if ( (object)x == null)  
      {  
         checked(i++);   // CS0201  
  
         // OK  
         checked {  
            i++;
         }  
      }  
   }  
}

See also