如何 grep 向量并返回单个 TRUE 或 FALSE? [英] How to grep a vector and return a single TRUE or FALSE?

问题描述

R 中是否有 grep 函数，如果在给定字符向量中的任何位置找到模式，则返回 TRUE，否则返回 FALSE?

Is there a grep function in R that returns TRUE if a pattern is found anywhere in the given character vector and FALSE otherwise?

我看到的所有函数都返回一个向量，表示找到的每个元素的当前位置.

All the functions I see return a vector of the current positions of each element found.

推荐答案

您在寻找任何"吗?

> x<-c(1,2,3,4,5)
> x==5
[1] FALSE FALSE FALSE FALSE  TRUE
> any(x==5)
[1] TRUE

请注意，您也可以对字符串执行此操作

Note that you can do this for strings as well

> x<-c("a","b","c","d")
> any(x=="b")
[1] TRUE
> any(x=="e")
[1] FALSE

与apply结合使用会很方便:

And it can be convenient when combined with applies:

> sapply(c(2,4,6,8,10), function(x){ x%%2==0 }  )
[1] TRUE TRUE TRUE TRUE TRUE
> any(sapply(c(2,4,6,8,10), function(x){ x%%2!=0 }  ))
[1] FALSE

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