我想使用gsub从我的字符串中删除或替换括号“(”或“)”。但是,如下所示,它不起作用。可能的原因是什么?
> k<-"(abc)"
> t<-gsub("()","",k)
> t
[1] "(abc)"
使用正确的正则表达式可以正常工作:
gsub("[()]", "", "(abc)")
额外的方括号意味着"匹配其中任何一个字符"。
k <- gsub("(", "", k, fixed = TRUE) # "Fixed = TRUE" disables regex
k <- gsub(")", "", k, fixed = TRUE)
k
[1] "abc"
gsub("\\(|)","","(abc)")
#[1] "abc"
`\(` => look for `(` character. `\` is needed as `(` a special character.
`|` => OR condition
`)` = Look for `)`