How to ignore Blank Cells while Concatenating cells in Excel
This post will guide you how to concatenate cells but ignore all blank cells in your worksheet in Excel. How do I concatenate cells but ignore blank cells with a formula in Excel. How to create a concatenate formula to skip blank cells with user defined function in Excel 2013/2016.
 Concatenating Cells but Ignore Blanks with a formula
 Concatenating Cells but Ignore Blanks with User Defined Function
Assuming that you have a list of data in range A1:A5 with one or two blank cells, and you want to concatenate those cells with a formula based on Concatenate function but ignore all blank cells. By default, the Concatenate function will combine all selected cells as well as those two blank cells. The below two methods will show you how to concatenate cells but skip all blanks.
Concatenating Cells but Ignore Blanks with a formula
To concatenate cells but ignore all blank cells in Excel, and you need to use a condition function to check whether the cell has a value or is empty cell. And if the cell is blank, then return nothing; otherwise, return the value of the cell. So you can use the below formula based on the concatenate and the ISBLANK function.
=CONCATENATE(IF(ISBLANK(A1),"",A1),IF(ISBLANK(A2),"",A2),IF(ISBLANK(A3),"",A3),IF(ISBLANK(A4),"",A4),IF(ISBLANK(A5),"",A5))
Type the above formula into a blank cell where you want to place the last result, and then press Enter key.
Concatenating Cells but Ignore Blanks with User Defined Function
There is another simple way to concatenate cells but skip all blank cells. And you can create one user defined function with VBA Macro code. Just do the following steps:
#1 open your excel workbook and then click on “Visual Basic” command under DEVELOPER Tab, or just press “ALT+F11” shortcut.
#2 then the “Visual Basic Editor” window will appear.
#3 click “Insert” >”Module” to create a new module.
#4 paste the below VBA code into the code window. Then clicking “Save” button.
Function ConcatenateButBlank(selectArea As Range) As String For Each oneCell In selectArea: finalResult = IIf(oneCell = "", finalResult & "", finalResult & oneCell & "_"): Next ConcatenateButBlank = Left(finalResult, Len(finalResult)  1) End Function
#5 back to the current worksheet, then type the following formula in a blank cell, and then press Enter key.
=ConcatenateButBlank(A1:A5)
Related Functions

Excel ISBLANK function
The Excel ISBLANK function returns TRUE if the value is blank or null.The syntax of the ISBLANK function is as below:= ISBLANK (value)… 
Excel IF function
The Excel IF function perform a logical test to return one value if the condition is TRUE and return another value if the condition is FALSE. The IF function is a buildin function in Microsoft Excel and it is categorized as a Logical Function.The syntax of the IF function is as below:= IF (condition, [true_value], [false_value])….