r - How to split character value properly -

i have data frame consists of composite information. split vector vectors "a" , "d", "a" corresponds numeric id 898, 3467 ,234 ,222 , vector "d" contains corresponding character values.

data:

a<-c("898_me","3467_you or ", "234_hi-hi", "222_what") b<-c(1,8,3,8) c<-c(2,4,6,2) df<-data.frame(a,b,c) 

what tried far:

a<-str(df$a)  a<-strsplit(df$a, split) 

but doesn't work out regular expression skills.

the required output table might have form:

                          d        b   c                       898   me       1   2                       3467  or   8   3                       234   hi-hi    3   6                       222       8   2    

library(tidyr)  a<-c("898_me","3467_you or ", "234_hi-hi", "222_what")  b<-c(1,8,3,8)  c<-c(2,4,6,2)  df <-data.frame(a,b,c)  final_df <- separate(df , , c("a" , "d") , sep = "_")  #          d b c #1  898      me 1 2 #2 3467 or  8 4 #3  234   hi-hi 3 6 #4  222    8 2  final_df$d  # [1] "me"      "you or " "hi-hi"   "what"