How can I do in Excel Flash Fill ?

the right answer is mr Reynaldo's answer

also u just can press CTRL + E  shortcut for flasfill

1-Click File > Options

2-Click Advanced and make sure the Automatically Flash Fill box is checked

3-Click OK, and restart your workbook

Flash fill is very useful  for integrating data without typing in each rows.

Like title (Mr.Ms., Name , Sur..

Ex: Column a - Mr. b. Jean c. Claud   -  if you put Mr J Claud then click Flash Fill then the succeeding rows will follow same result in row1.

By dragging the left-bottom side corner of the upper cell.

Please see demo linked below:

https://support.office.com/en-us/article/Use-AutoFill-and-Flash-Fill-2e79a709-c814-4b27-8bc2-c4dc84d49464