r - Split Date into Year and Month in data.table -

given,

 set.seed(1234)  library(data.table)  dt <- data.table(date=c(201405, 201406, 201501, 201503), x = rnorm(4, 0, 1))

return,

     date          x 1: 201405 -1.2070657 2: 201406  0.2774292 3: 201501  1.0844412 4: 201503 -2.3456977

i want split date year , month follows:

   year month          x 1: 2014     5 -1.2070657 2: 2014     6  0.2774292 3: 2015     1  1.0844412 4: 2015     3 -2.3456977

how can this?

converting comment answer, use substr combined assignment reference semantics. can wrap as.integer if prefer not return string

dt[, `:=`(year = substr(date, 1l, 4l), month = substr(date, 5l, 6l))]

Alconcel