How to reference column names that start with a number, in data.table

Question

If the column names in data.table are in the form of number + character, for example: 4PCS, 5Y etc, how could this be ref

Answer 1

You can also put an 'X' immediately before the variable name you are calling to get R to recognise it as a name rather than evaluating the number and the string as different (and hence bad syntax)

So e.g. when calling 4PCS use X4PCS

as in

mydata <- X4PCS