Pulling Initial Letters from a String

Re. the JoinAsText function in my most recent comment below, there was an error associated with recursion. Please locate the following statement
    text = text & JoinAsText(Delimiter, IgnoreEmpty, item) & Delimiter
and replace it with these statements
    Dim temp As String
    temp = JoinAsText(Delimiter, IgnoreEmpty, item)
    If Not (IgnoreEmpty And temp = "") Then text = text & temp & Delimiter
This has been corrected in My Excel Toolbox.
See https://sites.google.com/view/MyExcelToolbox/

My Excel Toolbox now includes the following function to combine values, arrays, and/or cell ranges into a delimited text string:
=JoinAsText(Delimiter,IgnoreEmpty,Values,...)
This function matches Excel 2019's TEXTJOIN; see https://support.microsoft.com/en-us/office/textjoin-function-357b449a-ec91-49d0-80c3-0e8fc845691c
If Delimiter is a null string (""), the result is the same as CONCAT.
Here is an abbreviated version:

Function JoinAsText(Delimiter As String, IgnoreEmpty As Boolean, _
    ParamArray Values() As Variant) As String
    Dim valu As Variant, item As Variant, text As String
    For Each valu In Values
        If IsArray(valu) Then
            For Each item In valu
                text = text & JoinAsText(Delimiter, IgnoreEmpty, item) _
                    & Delimiter
            Next item
        ElseIf IsError(valu) Then
            text = text & CStr(valu) & Delimiter
        ElseIf Not (IgnoreEmpty And valu = "") Then
            text = text & valu & Delimiter
        End If
    Next valu
    If text <> "" Then JoinAsText = Left(text, (Len(text) - Len(Delimiter)))
End Function

Notice this function is recursive.
See https://sites.google.com/view/MyExcelToolbox/

An alternative solution for users of earlier versions of Excel (tested using Excel2010) is to download UDFs for CONCAT and TEXTJOIN.
They work perfectly with J.Woolley's SplitText function.
Use Ctrl+Shift+Enter to convert to array formula.

UDF for CONCAT() is available here:
https://old.reddit.com/r/excelevator/comments/8w7b5p/udf_concat_textrange1_textrange2_concatenate/

UDF for TEXTJOIN() is available here:
https://old.reddit.com/r/excelevator/comments/5movbv/udf_textjoin_delimeter_ignore_blanks_valuerange/

I'm unsure about TEXTJOIN, but if using SplitText, the Trim() function does not seem to be required.

Re. my most recent comment below, if your version of Excel does not include TEXTJOIN or CONCAT here is a clever trick that permits use of CONCATENATE instead (with manual intervention). To get initials from a name in cell A1:
1. Enter the following formula in cell B1 (for example):
    =LEFT(SplitText(TRIM(A1)," "),1)
2. Select cell B1 and press F2 then Ctrl+A then F9 then Enter.
3. Select cell B1 and press F2 again, then edit the formula to replace curly brackets { } with parentheses ( ) and add CONCATENATE after the equal sign, then press Enter.
For example, if cell A1 contains the following text
    Rajeev    Kumar Pandey
after step 2 cell B1 should contain the array constant formula
    ={"R","K","P"}
and step 3 should convert that to the formula
    =CONCATENATE("R","K","P")
which returns the value
    RKP
See https://trumpexcel.com/concatenate-excel-ranges/

As noted by Allen, Alex Blakenburg's excellent formula currently requires Excel 365 because it uses TEXTSPLIT. If you don't have Excel 365, My Excel Toolbox includes the SplitText function described in my earlier comment here: https://excelribbon.tips.net/T013906_Splitting_Cells_to_Individual_Columns.html
Using SplitText, Alex's formula can be changed to
=TEXTJOIN("",TRUE,LEFT(SplitText(A1," "),1))
or with TRIM as discussed in my previous comment below
=TEXTJOIN("",TRUE,LEFT(SplitText(TRIM(A1)," "),1))
This formula can be simplified by using CONCAT instead of TEXTJOIN:
=CONCAT(LEFT(SplitText(TRIM(A1)," "),1))
I believe TEXTJOIN and CONCAT both require Excel 2019 or later.
See https://sites.google.com/view/MyExcelToolbox/

The last formula in my previous comment below had an error. It should have been
    =TEXTJOIN("",TRUE,LEFT(TEXTSPLIT(TRIM(A1)," "),1))
Sorry about that.

Re. the Tip's Initials function, it should be noted that VBA's Trim function does not work the same as Excel's TRIM function. Excel's TRIM removes all spaces from text except for single spaces between words. VBA's Trim only removes leading and trailing spaces. Therefore, if Raw has 2 words separated by 2 spaces, the following statement
    Temp = Split(Trim(Raw))
will return 3 substrings, not 2. However, the 2nd substring is null (zero-length), so the macro doesn't care because
    Left(Temp(J), 1)
returns the null string for this case.
This issue can be avoided by replacing the first statement above with
    Temp = Split(WorksheetFunction.Trim(Raw))
For the same reasons, Alex Blakenburg's function could be changed to
    =TEXTJOIN("",TRUE,LEFT(TEXTSPLIT(TRIM(A1," "),1))
but it matters less because the 2nd argument of TEXTJOIN is TRUE (ignore empty).

Awesome formula, Alex, for those using the version of Excel with Microsoft 365.

This will produce the same result as the Macro Function Initials
=TEXTJOIN("",TRUE,LEFT(TEXTSPLIT(A1," "),1))