Parameter modifier 'this' should be the first parameter of extension method

• Jun 26, 2019

CodeRush Classic shows the Parameter modifier ‘this’ should be the first parameter of extension method code issue if the parameter with the this modifier is not the first parameter of an extension method.

Fix

Place the parameter with the this modifier at the first position.

Purpose

Highlights the member declarations, which would cause the Method has a parameter modifier ‘this’ which is not on the first parameter compilation error.

Example

C#

public static IEnumerable │GetValues(bool positiveOnly, this int[] intArray)
{
    List<int> result = new List<int>();
    foreach (int value in intArray)
        if (!positiveOnly || value > 0)
            result.Add(value);
    return result;
}

Fix:

C#

public static IEnumerable GetValues(this int[] intArray, bool positiveOnly)
{
    List<int> result = new List<int>();
    foreach (int value in intArray)
        if (!positiveOnly || value > 0)
            result.Add(value);
    return result;
}