Check if a string is alphanumeric (letters, digits, or underscores)

This function tests whether the input string consists entirely of letters (a–z, A–Z), digits (0–9), or underscores (_).

Usage

is_word_num(ch)

Arguments

ch

A character string or vector of strings to test.

Value

A logical vector the same length as ch, where each element is TRUE if the corresponding string contains only alphanumeric characters and underscores, FALSE otherwise.

Examples

is_word_num("alpha123")     # TRUE
#> [1] TRUE
is_word_num("var_1")        # TRUE
#> [1] TRUE
is_word_num("a-b")          # FALSE
#> [1] FALSE
is_word_num(c("abc", "123", "a_b", "x-y"))  # TRUE, TRUE, TRUE, FALSE
#> [1]  TRUE  TRUE  TRUE FALSE