Making a character string with column names with zero values

Question

The 4th column is my desired column. Video,Webinar,Meeting,Conference are the 4 type of activities that the different customers(names) can engage in. You can see,in a given row,

Answer 1

Here you go:

setcolorder(dt, c("Name", "Webinar", "Meeting", "Conference", "Video", "NextStep"))
dt[, NextStepNew:=apply(dt, 1, function(x) paste0(names(x)[x==0], collapse=","))][]
   Name Webinar Meeting Conference Video                   NextStep                NextStepNew
1: John       0       0          0     1 Webinar,Meeting,Conference Webinar,Meeting,Conference
2: John       1       0          0     1         Meeting,Conference         Meeting,Conference
3: John       1       1          0     1                 Conference                 Conference
4:  Tom       0       1          0     0   Webinar,Conference,Video   Webinar,Conference,Video
5:  Tom       0       1          1     0              Webinar,Video              Webinar,Video
6: Kyle       0       0          1     0      Webinar,Meeting,Video      Webinar,Meeting,Video