R字符串处理stringr

library(stringr)
 
# 合并字符串
fruit <- c("apple","banana","pear","pinapple")
res <- str_c(1:4,fruit,sep=' ',collapse=' ')
str_c('I want to buy ',res,collapse=' ')
 
# 计算字符串长度
str_length(c("i","like","programming R",123,res))
 
# 按位置取子字符串
str_sub(fruit,1,3)
# 子字符串重新赋值
capital <-toupper(str_sub(fruit,1,1))
str_sub(fruit,rep(1,4),rep(1,4))<- capital 
 
# 重复字符串
str_dup(fruit,c(1,2,3,4))
 
# 加空白
str_pad(fruit,10,"both")
# 去除空白
str_trim(fruit)
 
#  根据正则表达式检验是否匹配
str_detect(fruit,"a$")
str_detect(fruit,"[aeiou]")
 
# 找出匹配的字符串位置
str_locate(fruit,"a")
 
# 提取匹配的部分
str_extract(fruit,"[a-z]+")
str_match(fruit,"[a-z]+")
 
# 替换匹配的部分
str_replace(fruit,"[aeiou]","-")
 
# 分割
str_split(res," ")