Why is this an issue?

Nested control flow statements If, Select, For, For Each, While, Do, and Try are often key ingredients in creating what’s known as "Spaghetti code". This code smell can make your program difficult to understand and maintain.

When numerous control structures are placed inside one another, the code becomes a tangled, complex web. This significantly reduces the code’s readability and maintainability, and it also complicates the testing process.

How to fix it

Code examples

The following example demonstrates the behavior of the rule with the default threshold of 3 levels of nesting:

Noncompliant code example

If condition1 ' Compliant - depth = 1
  ' ...
  If condition2 ' Compliant - depth = 2
    ' ...
    For i = 0 to 10 ' Compliant - depth = 3, not exceeding the limit
      ' ...
      If condition4 ' Noncompliant - depth = 4
        If condition5 ' Depth = 5, exceeding the limit, but issues are only reported on depth = 4
          ' ...
        End If
        Return
      End If
    Next
  End If
End If