CRR0015 - Logical OR expression redundancy

Feb 28, 2025

This analyzer detects logical expressions that contain the same logical variable on both sides of the logical OR expression. For instance, consider the following conditional expression.

C#
VB.NET

csharp

if (a || a && b){ // CRR0015
    // ...
}

If a OrElse (a AndAlso b) Then ' CRR0015
    ' ...
End If

Such expressions may appear by mistake. Refer to the truth table of the conditional expression from the example above.

| a | b | a && b | a || (a && b) | | --- | --- | --- | --- | | True | True | True | True | | True | False | False | True | | False | True | False | False | | False | False | False | False |

As you can see, the last column is similar to the a column, which means that the expression equals the a variable value. Since the value of the b variable is not considered in this expression, it probably contains a mistake. You can fix it manually according to the desired logic or use the Simplify Expression refactoring to automatically shorten this expression.

C#
VB.NET

csharp

if (a){
    // ...
}

If a Then
    ' ...
End If