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Is there simpler method to match regex pattern in its entirety? For example, to check if given string is uppercase the following 2 methods but seem too complex. Checking stringr I found no indication for simpler solution either.
Method 1:
isUpperMethod1 <- function(s) { return (all(grepl("[[:upper:]]", strsplit(s, "")[[1]]))) } Method 2:
isUpperMethod2 <- function(s) { m = regexpr("[[:upper:]]+", s) return (regmatches(s, m) == s) } I intentionally omit handling of empty, NA, NULL strings to avoid bloated code.
The uppercase pattern can be generalized to arbitrarily regex pattern (or character set).
I see no problems with both solutions above except that they seem excessively complex for the problem solved.
921
To check if a letter in a string is uppercase or lowercase use the toUpperCase() method to convert the letter to uppercase and compare it to itself. If the comparison returns true , then the letter is uppercase, otherwise it's lowercase. Copied!
tolower() method in R programming is used to convert the uppercase letters of string to lowercase string. Return: Returns the lowercase string.
toupper() method in R programming is used to convert the lowercase string to uppercase string. Syntax: toupper(s) Return: Returns the uppercase string.
There should be no difference.
You can use the ^ and $ patterns to match the beginning and end of the string
grepl("^[[:upper:]]+$", s) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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