FILTER

FILTER(sourcearray, match [,include] [,compare])

Returns an array containing a subset of values that contain a substring (Variant).

sourcearray	The array of strings to be searched (1-dimensional) (Variant / Array)
match	The text string to search for (String).
include	(Optional) Whether to return substrings that include or exclude match: True = subset does include the match (default) False = subset does not include the match
compare	(Optional) A vbCompareMethod constant specifying the type of string comparison to use (Integer): -1 = vbUseCompareOption (uses the "Option Compare" setting) 0 = vbBinaryCompare (case sensitive) (default) 1 = vbTextCompare (not case sensitive) 2 = vbDatabaseCompare (uses an Access database)

REMARKS

* This function performs a Partial Match. There is no way to specify matching the entire element or just part of it.
* This function is case sensitive (by default).
* This function does not support wildcards (? and *).
* This function will always return a 0 based array.
* This function always returns a 1 dimensional array.
* This function ignores any Option Base 1 statements and always creates an array that starts at 0.
* This function searches an array for all the elements that match a given text string and returns an array of just the elements that match.
* If no matches of "match" are found within "sourcearray", then an empty array is returned.
* If "sourcearray" is Null, then a "type mismatch" run-time error occurs.
* If "include" = True, then the subset is all the values that does include the substring "match".
* If "include" = False, then the subset is all the values that do not include the substring "match".
* If "include" is left blank, then True is used.
* If "compare" is left blank, then -1 is used. If there is no Option Compare statement provided then vbBinaryCompare (0) is used.
* If "compare" is Null, then an error occurs.
* The array that is returned only contains enough elements to contain the number of matched items.
* This function can be used to determine if a particular element exists in a 1-dimensional array.
* This function can return an empty array. When this happens the lowerbound is 0 and the upperbound is -1.
* You can use the ARRAY function to return an array containing specific values.
* You can use the JOIN function to return a text string containing all the elements in an array.
* You can use the SPLIT function to return an array containing a specified number of substrings.
* The equivalent .NET function is Microsoft.VisualBasic.Strings.Filter
* For the Microsoft documentation refer to learn.microsoft.com

Dim aValues(2) As String 
aValues(0) = "This" 
aValues(1) = "is" 
aValues(2) = "it" 

Dim aSubStrings() As String 
aSubStrings = Filter(aValues, "is") 
Debug.Print aSubStrings(0) = "This" 
Debug.Print aSubStrings(1) = "is" 
Debug.Print VBA.Join(aSubStrings, ",")   '= This,is  

aSubStrings = Filter(aValues, "i") 
Debug.Print VBA.Join(aSubStrings, ",")   '= This,is,it  

'Return the values that do not contain "is"
aSubStrings = Filter(aValues, "is", False) 
Debug.Print VBA.Join(aSubStrings, ",")   '= it  

aSubStrings = Filter(aValues, "is", , VBA.VbCompareMethod.vbTextCompare) 
Debug.Print VBA.Join(aSubStrings, ",")   '= This,is  

aSubStrings = Filter(aValues, "is", True, VBA.VbCompareMethod.vbTextCompare) 
Debug.Print VBA.Join(aSubStrings, ",")   '= This,is  

Return the values that contain "IS" not case sensitive 
aSubStrings = Filter(aValues, "IS", True, vbTextCompare) 
Debug.Print VBA.Join(aSubStrings, ",")   '= This,is  

aSubStrings = Filter(aValues, "IS") 
Debug.Print "'" & VBA.Join(aSubStrings, ",") & "'"   '= blank  

aSubStrings = Filter(aValues, "i", False) 
Debug.Print "'" & VBA.Join(aSubStrings, ",") & "'"   '= blank  

aSubStrings = Filter(aValues, "?s") 
Debug.Print "'" & VBA.Join(aSubStrings, ",") & "'"   '= blank