regex - R remove first character from string

Question

I can remove the last character from a string:

listfruit  <- c("aapplea","bbananab","oranggeo")
gsub('.{1}$', '', listfruit)

But I am having problems trying to remove the first character from a string. And also the first and last character. I would be grateful for your help.

Answer 1

If we need to remove the first character, use sub, match one character (. represents a single character), replace it with ''.

sub('.', '', listfruit)
#[1] "applea"  "bananab" "ranggeo"

Or for the first and last character, match the character at the start of the string (^.) or the end of the string (.$) and replace it with ''.

gsub('^.|.$', '', listfruit)
#[1] "apple"  "banana" "rangge"

We can also capture it as a group and replace with the backreference.

sub('^.(.*).$', '\1', listfruit)
#[1] "apple"  "banana" "rangge"

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Another option is with substr

substr(listfruit, 2, nchar(listfruit)-1)
#[1] "apple"  "banana" "rangge"