Concatinate the text of each row

Good day!
I'm new to excel and I'm trying to concatenate the text in 3 cells and print in the 4th cell

col1(A) col2(B) col3 (C) col4 (D)
====================================
text1 text2 text3 text1+text2+text3
text2 text3 text4 text2+text3+text4
text5 text6 text7 text5+text6+text7
-- -- --
-- -- --

There are more than 100 rows

I can use this function for each row
=CONCATENATE(A1,B1,C1) and print the result in D1 cell

again I go to the next row
=CONCATENATE(A2,B2,C2) and print the result in D2 cell

I want to select the entire D column and fill each D column cells without going into each D cells and apply the function

Could somebody please help me?

Thank you!

Enter your formula in cell D1, there'll be a little black square in the bottom right hand corner of cell D1 - double-click on this and it will copy your formula down to the end of the data.

based on the assumption that i have understood your requirement correctly, following are some suggestions:

the CONCATENATE function can also be achieved with the '&'.

so, in D1, you can simply put =a1&b1&c1

and then drag-fill this formula down to as many rows as you want; you will not have to keep entering the formula in every cell along column D.

the same is true for the CONCATENATE formula you have written; enter it once and drag-fill down.

you can also double-click on the drag-fill handle (black square at right-bottom) to have the formula auto-populate along column D until the row where first blank is found in the adjacent column C.

alternately, you can select the entire column D by clicking on the letter 'D' (you will observe that D1 is white, rest of the column is highlighted). hit F2, then enter your formula (either the CONCATENATE or the &), which will appear in D1. then confirm with CTRL+ENTER.