Fill in blank Excel cells using value from another column?

Question

Similar to Fill non-contiguous blank cells with the value from the cell above the first blank but using an adjacent column instead.

I have something like this:

For all the blank values in column A, I would like it to be populated with the matching value from column C. So A2 would be populated with C2 and A4 with C4.

Answer 1

In a new column D, you can use the formula =IF(ISBLANK(A4), C4, A4) and that would output:

A   B   C   D
-------------
X   Y   Y   X
    G   R   R
e   9   T   e
    K   7   7