S1645 — The "&" operator should be used to concatenate strings

Why is this an issue?

Consistently using the & operator for string concatenation make the developer intentions clear.

&, unlike +, will convert its operands to strings and perform an actual concatenation.

+ on the other hand can be an addition, or a concatenation, depending on the operand types.

Noncompliant code example

Module Module1
    Sub Main()
        Console.WriteLine("1" + 2) ' Noncompliant - will display "3"
    End Sub
End Module

Compliant solution

Module Module1
    Sub Main()
        Console.WriteLine(1 & 2)   ' Compliant - will display "12"
        Console.WriteLine(1 + 2)   ' Compliant - but will display "3"
        Console.WriteLine("1" & 2) ' Compliant - will display "12"
    End Sub
End Module