Get the index of the values of one vector in another?

Question

I would guess this is a duplicate, but I can\'t find that so here goes...

I\'d like to return the index of second in first:

first = c( \"a\" , \"c\"          


        

Answer 1

Getting indexes of values is what match() is for.

 first = c( "a" , "c" , "b" )
 second = c( "c" , "b" , "a" )
 match(second, first)
 [1] 2 3 1