How do I test if three variables are equal [R]

Question

I'm trying to do if else statement which includes a condition if three variables in the data frame equal each other.

I was hoping to use the identical function but not sure whether this works for three variables.

I've also used the following but R doesn't seem to like this:

geno$VarMatch  <- ifelse((geno[c(1)] != '' & geno[c(2)] != '' & geno[c(3)] != '') 
& (geno[c(5)] == geno[c(4)] == geno[c(6)]), 'Not Important', 'Important')

Keeps telling me:

Error: unexpected '==' 

Am I supposed to specify something as data.frame/vector etc... Coming from an SPSS stand point, I'm slightly confused.

Sorry for the simplistic query.

Answer 1

I see so complicated results, mine is simple:

all(sapply(list(a,b,c,d), function(x) x == d))

returns TRUE, if all equals d all equals each other.

Answer 2

Here's a recursive function which generalises to any number of inputs and runs identical on them. It returns FALSE if any member of the set of inputs is not identical to the others.

ident <- function(...){
    args <- c(...) 
    if( length( args ) > 2L ){
       #  recursively call ident()
       out <- c( identical( args[1] , args[2] ) , ident(args[-1]))
    }else{
        out <- identical( args[1] , args[2] )
    }    
    return( all( out ) )
}

ident(1,1,1,1,1)
#[1] TRUE
ident(1,1,1,1,2)
#[1] FALSE