How to use cbind() when columns stored in a character vector?

Question

Let\'s say I have the below data.table:

DT <- data.table(x=rep(c(1,2),3),y=rep(1,6),z=rep(2,6))

DT
   x y z
1: 1 1 2
2: 2 1 2
3: 1 1 2
4: 2 1 2
5: 1 1 2
6