Thank you very much for your suggestions

Does anyone have any suggestions what the default value should be assign for
each empty cell?
I would like to assign the default value for if statement on row 1, such as
If(True, any number, default), but I cannot assign "" into formula
If(True, any number, ""), which does not work for following statement,
because of this character "".
Enter with CTRL + SHIFT + ENTER
=MAX(IF(ABS($A$1:$D$1-A2)=MIN(ABS($A$1:$D$1-A2)),$A$1:$D$1))
Does anyone have any suggestions?
Thank for any suggestions
Eric