Compiler Error CS1947

Range variable 'variable name' cannot be assigned to -- it is read only.

A range variable is like an iteration variable in a foreach statement. It cannot be assigned to in a query expression.

To correct this error

1. Remove the assignment to the range variable.

2. If necessary, introduce a new range variable by using the let clause and use it to store the value.

Example

The following code generates CS1947:

// cs1947.cs
using System.Linq;
class Test
{
    static void Main()
    {
        int[] array = new int[] { 1, 2, 3, 4, 5 };
        var x = from i in array
                let k = i
                select i = 5; // CS1947
        x.ToList();
    }
}

See Also

Concepts

LINQ Query Expressions (C# Programming Guide)