Count values separated by a comma in a character string

I have this example data

d<-"30,3"
class(d)

I have this character objects in one column in my work data frame and I need to be able to identify how many numbers it has.

I have tried to use length(d), but it says 1

After looking for solution here I have tried

eval(parse(text='d'))
as.numeric(d)
as.vector.character(d)

But it still doesn't work.

Any straightforward approach to solve this problem?

These two approaches are each short, work on vectors of strings, do not involve the expense of explicitly constructing the split string and do not use any packages. Here d is a vector of strings such as d <- c("1,2,3", "5,2") :

1) count.fields

count.fields(textConnection(d), sep = ",")

2) gregexpr

lengths(gregexpr(",", d)) + 1

You could use scan.

 v1 <- scan(text=d, sep=',', what=numeric(), quiet=TRUE)
 v1
 #[1] 30  3

Or using stri_split from stringi. This should take both character and factor class without converting explicitly to character using as.character

library(stringi)
v2 <- as.numeric(unlist(stri_split(d,fixed=',')))
v2
#[1] 30  3

You can do the count using base R by

length(v1)
#[1] 2

Or

nchar(gsub('[^,]', '', d))+1
#[1] 2

Visualize the regex

 [^,]

Debuggex Demo

Update

If d is a column in a dataset df and want to subset rows with number of digits equals 2

  d<-c("30,3,5","30,5") 
  df <- data.frame(d,stringsAsFactors=FALSE)
  df[nchar(gsub('[^,]', '',df$d))+1==2,,drop=FALSE]
  #    d
  #2 30,5

Just to test

  df[nchar(gsub('[^,]', '',df$d))+1==10,,drop=FALSE]
  #[1] d
  #<0 rows> (or 0-length row.names)