How to select first 2 digits of a number? I just need the name of the function
Example: 12455 turns into 12, 13655 into 13
Basically it's the equivalent of substring for integers.
2 Answers
If at the end you need again a numeric vector/element, you can use
as.numeric(substr(x, 1, 2))
This solution uses gsub, the anchor ^ signifiying the start position of a string, \\d{2} for any two digits appearing at this position, wrapped into (...) to mark it as a capturing group, and backreference \\1 in the replacement argument, which 'recalls' the capturing group:
x <- c(12455,13655)
gsub("(^\\d{2}).*", "\\1", x)
[1] "12" "13"
Alternatively, use str_extract:
library(stringr)
str_extract(x, "^\\d{2}")
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