从[A-Z]中提取包含字符串的值

Question

我试图从矢量中动态提取那些带有[A-Z]字符串的值（它们也可能包含数字），而不是在“str”中指定它们

我的代码如下：

strings <- c("1", "70.5", "sh", "av", "3", "12","as","da","da","azz1")
     str <- c("sh", "av","as","da","azz1")
    matches <- unique (grep(paste(str,collapse="|"), 
                            strings, value=TRUE))

Answer 1

你可以尝试：

> unique(grep("^[a-zA-Z]", strings, value = TRUE))
[1] "sh"   "av"   "as"   "da"   "azz1"

这应该允许您以小写和大写字符开头的字符串。另一个大写字符的例子：

> strings2 <- c("1", "70.5", "sh", "aV", "3", "12","as","da","da","azz1","DA")
> unique(grep("^[a-zA-Z]", strings2, value = TRUE))
[1] "sh"   "aV"   "as"   "da"   "azz1" "DA"