c# - How to add a value to a existing .csv file -

i have information in .csv file @ click of button, add 1 number.

so data table:

years last paid: 2012 2012 2012 2012 

and @ click of button, on selected columns

years last paid:  2013 2013 2012 2013  

so in laymans terms, how add 1 selected column when press button

i dont have attempt because dont know how google search it, if there questions please ask, have in 3 hours present

try this

list<string> str = file.readalltext(@"completefilepath").split('\n').tolist(); list<string> updatedvalues =   new list<string>(); foreach (var value in str) {       int val = 0;       if (int.tryparse(value, out val))       {          updatedvalues.add((val + 1).tostring());               } }  file.writealllines(@"completefilepath", updatedvalues);