How to find out the index of an element present in  a vector in R? Explain with an example                     
                        
                           
                           
                        
                     
                  
                  
                  To find out the index of an element, we have a function called match which returns the first encounter of a match. Let us define a vector of 10 random elements.
random_samples <- sample(1:10) 
Random_samples
Output 
[1] 10  9  6  8  1  3  4  7  5  2
Now we will apply match to find out the index
match(c(4,8),random_samples)
Output
[1] 7 4
In case if we want multiple matching, we can use a pipe operator as follows
random_samples<- sample(1:4,10,replace=TRUE)
random_samples
[1] 1 2 2 2 1 1 1 2 2 4
which(random_samples %in% c(2,4))
 
 
