CRR0015 - Logical OR expression redundancy

• Oct 17, 2018

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#

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

VB.NET

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#

if (a){
    // ...
}

VB.NET

If a Then
    ' ...
End If