Compiler Error CS0844

  • Article

Cannot use local variable 'name' before it is declared. The declaration of the local variable hides the field 'name'.

An identifier can have only one meaning in a given block. Local variables that have the same name as class fields can hide the field by introducing a second meaning for the identifier. Therefore the compiler generates an error when you refer to a class field in a method, and then declare a local variable by the same name.

To correct this error

  • Use this.num to refer to the class field.

  • Give the local variable a different name from the class field.

Example

The following code generates CS0844:

class Test
    {
        int num;
        public void TestMethod()
        {
            num = 5; // CS0844
            int num = 6;        }
        public static int Main()
        {
            return 1;
        }
    }