R function 用于删除列中的前 4 个字符？

Question

I have a data frame (Data) and I have created a new column with the first four characters of each vector in a column (Details) using substr.

Here is the code:

Data$Years = substr(Data$Details, 1, 5)

How would I use substr (or another function) to remove the same first four characters from the original (Details) column?

Answer 1

We can specify the first (in substring ) or start in substr as the 5th character and last (not needed in substring as it is by default last = 1000000L ) or stop in substr as the last character ( nchar )

substring(Data$Details, 5)

Or with substr

substr(Data$Details, 5, nchar(Data$Details))

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Or using a regex to match any character ( . - repeated 4 times) from the start ( ^ ) of the string and replace with blank ( "" )

sub("^....", "", Data$Details)