strsplit()函数

strsplit()函数

strsplit主要是根据子字符串中与此相匹配的字符将向量进行分割，分割后的内容不包含该字符的列表。

分割后的数据类型为列表

unlist(strsplit(test,split = ","))  ## 加unlist函数，后转化为字符串

R语言中常使用strsplit()函数对字符串进行分割。
语法

##设置fixed = T,正常拆分，参数作用为精确匹配，屏蔽正则表达式

> s <- '123 456'
> strsplit(s,'')
[[1]]
[1] "1" "2" "3" " " "4" "5" "6"

> strsplit(s, ' ')
[[1]]
[1] "123" "456"

> strsplit(s, ' ')[1]
[[1]]
[1] "123" "456"

> strsplit(s, ' ')[[1]][1]
[1] "123"

> x <- c(as = "asfef", qu = "qwerty", "yuiop[", "b", "stuff.blah.yech")
> x
               as                qu                                                       
          "asfef"          "qwerty"          "yuiop["               "b" "stuff.blah.yech" 
> strsplit(x, "e")
$as
[1] "asf" "f"  
$qu
[1] "qw"  "rty"
[[3]]
[1] "yuiop["
[[4]]
[1] "b"
[[5]]
[1] "stuff.blah.y" "ch"          

> x = c("abcde", "ghij", "klmnopq")                   #x 为三个字条串组成的向量
> strsplit(x, "", fixed=TRUE)                               #用strsplit 把每个字符串中的字符给分离出来形成列表中单独的元素，总共有三个元素
[[1]]
[1] "a" "b" "c" "d" "e"
[[2]]
[1] "g" "h" "i" "j"
[[3]]
[1] "k" "l" "m" "n" "o" "p" "q"       

3、指定输出结果为向量

> test <- "aa,bb,cc,dd,ee" ##生产测试数据
> a <- strsplit(test,split = ",") 
> a
[[1]]
[1] "aa" "bb" "cc" "dd" "ee"

> class(a)
[1] "list"
> b <- unlist(strsplit(test,split = ","))  ## 加unlist函数
> b
[1] "aa" "bb" "cc" "dd" "ee"
> class(b)   
[1] "character"