R - <em>substring()</em>: wrapper for <em>substr()</em>

substring: wrapper for substr

substring(text=month.name, first=1, last=3)
# [1] "Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"
substr(x=month.name, start=1, stop=3)
# [1] "Jan" "Feb" "Mar" "Apr" "May" "Jun" "Jul" "Aug" "Sep" "Oct" "Nov" "Dec" 

R - substring(): wrapper for substr()