StringBuilder is more efficient than string concatenation, especially when the operator is repeated over and over as in loops.
Noncompliant code example
Module Module1
Sub Main()
Dim foo = ""
foo &= "Result: " ' Compliant - outside of loop
For i = 1 To 9
foo &= i ' Noncompliant
Next
End Sub
End Module
Compliant solution
Module Module1
Sub Main()
Dim foo = New System.Text.StringBuilder
foo.Append("Result: ") ' Compliant
For i = 1 To 9
foo.Append(i) ' Compliant
Next
End Sub
End Module
