4.4 base 和 stringr
以下表格数据对比，主要是 base R 和 stringr 中相应字符处理功能函数对比。
表格数据来源stringr and base differences。表格数据可用以下代码获取(注意网络):
library(tidyverse)
library(rvest)
dt <- read_html('https://stringr.tidyverse.org/articles/from-base.html') %>%
html_table() %>% `[[`(1)| base | stringr |
|---|---|
| gregexpr(pattern, x) | str_locate_all(x, pattern) |
| grep(pattern, x, value = TRUE) | str_subset(x, pattern) |
| grep(pattern, x) | str_which(x, pattern) |
| grepl(pattern, x) | str_detect(x, pattern) |
| gsub(pattern, replacement, x) | str_replace_all(x, pattern, replacement) |
| nchar(x) | str_length(x) |
| order(x) | str_order(x) |
| regexec(pattern, x) + regmatches() | str_match(x, pattern) |
| regexpr(pattern, x) + regmatches() | str_extract(x, pattern) |
| regexpr(pattern, x) | str_locate(x, pattern) |
| sort(x) | str_sort(x) |
| strrep(x, n) | str_dup(x, n) |
| strsplit(x, pattern) | str_split(x, pattern) |
| strwrap(x) | str_wrap(x) |
| sub(pattern, replacement, x) | str_replace(x, pattern, replacement) |
| substr(x, start, end) | str_sub(x, start, end) |
| tolower(x) | str_to_lower(x) |
| tools::toTitleCase(x) | str_to_title(x) |
| toupper(x) | str_to_upper(x) |
| trimws(x) | str_trim(x) |
通过以上对比，方便我们从 Base R 切换到 stringr 包的使用。