What does zero index signify in R?

r

#1

I was studying about vectors in R and I have studied that in R indexing start from 1 not zero but what will happen when we try to access the zeroth position in R?
For ex

x<-1:10
X[0] 

signifies?


#2

In R, the indexing begins from 1. While NA and zero values are allowed as indexes, rows of an index matrix containing a zero are ignored, whereas rows containing an NA produce an NA in the result.
See the below result:

x<-1:10
x[c(0, 1,2,3, NA,4,0)]
[1]  1  2  3 NA  4