https://stackoverflow.com/questions/355907/how-do-i-repeat-an-edit-on-multiple-lines-in-vim
1
for the text:
1abc123abc2def456def3ghi789ghiyou do:
1Ctrl - v2jj # select 3 lines3Shift - I4, # insert a comma5Esc # at this moment, three commas gonna be addedyou get:
1abc,123abc2def,456def3ghi,789ghi2
use ctrl + v to and move cursor, you’ll select several lines, you can do operations in normal mode, for example x to delete a character.