There are multiple functions and operators that can be used to search elements in list or vector.
A few of them are,
1. %in%  - returns TRUE/FALSE based on whether the element is found or not found.
Syntax: v1 %in% v2
2.  match()  - similar to %in% but in the form of a function. Match() returns a vector of the positions of (first) matches of its first argument in its second. 
Syntax: 
match(x, table, nomatch = NA_integer_, incomparables = NULL)
3.  is.element - is.element(x, y) is identical to x %in% y. 
syntax: 
is.element(x, y)