How to detect that a vector is subset of specific vector?

Question

I have two vectors (sets) like this:

first<-c(1,2,3,4,5)
second<-c(2,4,5)

how can I detect that whether second is subset

Answer 1

Here's another

setequal(intersect(first, second), second)
## [1] TRUE

Or

all(is.element(second, first))
## [1] TRUE

Answer 2

If the order of the array elements matters, string conversion could help:

ord_match <- function(x,y){
    m <- c(0,grep(paste0(x,collapse=""),
                  paste0(y,collapse=""), fixed = T))
    return(as.logical(m)[length(m)])
}

Answer 3

Here's one way

> all(second %in% first)
[1] TRUE