Function for strings (ConcatIf) like SumIf

[passat]

Is there function for string like SumIf (concatenate instead sum)?

[JohnSUN]

Yes, for this task you can use combination of functions TEXTJOIN() and IF()
For example, if you have in range A2:A100 some text strings and in range B2:B100 condition for concatenate (or skip any cells) then use array formula like as

{=TEXTJOIN(", ";1;IF(B2:B100;A2:A100;""))}

[passat]

User function:

Function ConcatIf ( compareRange As Variant, xCriteria As String, stringsRange As Variant, Optional Delimiter As String)

Dim nConcatif As String

nConcatif = “”

For i = 1 To ubound ( compareRange, 1 )

  If  compareRange (  i, 1 ) = xCriteria Then
      nConcatIf = nConcatIf & Delimiter & stringsRange ( i, 1 )           
  End If

Next i

nConcatIf=Mid(nConcatIf, Len(Delimiter) + 1)

ConcatIf = nConcatIf

End Function