How to split a string vector that contain strings of equal sizes and have spaces between values then extract only few values in R?

A string vector can contain any value including spaces. Sometimes a string vector is read with some spaces as well and we want to split the vector then extract few values. For example, if a string has “ABC 123” then we might want to extract the number 123 so that we can use it in analysis. If the string vector has strings of equal sizes then it can be easily done with the help of substr function.

Examples

> x1<-c("1 00","1 01","1 02","1 03","1 03","1 04")
> x1
[1] "1 00" "1 01" "1 02" "1 03" "1 03" "1 04"
> Numeric_Last_two_x1<-substr(x1,start=4,stop=5)
> Numeric_Last_two_x1
[1] "00" "01" "02" "03" "03" "04"
> Numeric_Last_first_x1<-substr(x1,start=4,stop=4)
> Numeric_Last_first_x1
[1] "0" "0" "0" "0" "0" "0"
> Numeric_Last_last_x1<-substr(x1,start=5,stop=5)
> Numeric_Last_last_x1
[1] "0" "1" "2" "3" "3" "4"
> x2<-c("1 0","1 1","1 2","1 3","1 4","1 5")
> x2
[1] "1 0" "1 1" "1 2" "1 3" "1 4" "1 5"
> Last_value_x2<-substr(x2,start=4,stop=4)
> Last_value_x2
[1] "0" "1" "2" "3" "4" "5"
> First_value_x2<-substr(x2,start=1,stop=1)
> First_value_x2
[1] "1" "1" "1" "1" "1" "1"
> x3<-c("A 0","B 1","C 2","D 3","E 4","F 5")
> x3
[1] "A 0" "B 1" "C 2" "D 3" "E 4" "F 5"
> Last_value_x3<-substr(x3,start=4,stop=4)
> Last_value_x3
[1] "0" "1" "2" "3" "4" "5"
> x4<-c("A 1151","B 1152","C 1153","D 1154","E 1155","F 1156")
> x4
[1] "A 1151" "B 1152" "C 1153" "D 1154" "E 1155" "F 1156"
> Last_value_x4<-substr(x4,start=7,stop=7)
> Last_value_x4
[1] "1" "2" "3" "4" "5" "6"
> Last_three_value_x4<-substr(x4,start=5,stop=7)
> Last_three_value_x4
[1] "151" "152" "153" "154" "155" "156"
> Last_two_value_x4<-substr(x4,start=6,stop=7)
> Last_two_value_x4
[1] "51" "52" "53" "54" "55" "56"
> Last_numeric_value_x4<-substr(x4,start=4,stop=7)
> Last_numeric_value_x4
[1] "1151" "1152" "1153" "1154" "1155" "1156"
> x5<-c("System-1 191","System-2 352","System-3 498","System-4 154","System-5
327","System-6 456")
> x5
[1] "System-1 191" "System-2 352" "System-3 498" "System-4 154"
[5] "System-5 327" "System-6 456"
> Last_numeric_value_x5<-substr(x5,start=11,stop=13)
> Last_numeric_value_x5
[1] "191" "352" "498" "154" "327" "456"
> Last_digit_x5<-substr(x5,start=13,stop=13)
> Last_digit_x5
[1] "1" "2" "8" "4" "7" "6"
> Last_two_digits_x5<-substr(x5,start=12,stop=13)
> Last_two_digits_x5
[1] "91" "52" "98" "54" "27" "56"
> Digits_in_System_x5<-substr(x5,start=8,stop=8)
> Digits_in_System_x5
[1] "1" "2" "3" "4" "5" "6"