The CONTAINS or ? operator can be used to search a character variable for a user-specified string. This operator is case-sensitive, and can only be used within a WHERE statement. CONTAINS is similar to the index function, however, it does not provide the position of the character string within the variable.

The data steps below are equivalent. CONTAINS and ? are interchangeable.

data check;
    set sashelp.zipcode;
    where countynm contains 'z';
run;
 
data check;
    set sashelp.zipcode;
    where countynm ? 'z';
run;

Thanks to Mary Rosenbloom for posting this tip on sasCommunity.org!