The ArrayList Method IndexOf Has the Following API

Short Answer

The ArrayList method indexOf has the following API:
public int indexOf( HYPERLINK "http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html" \o "class in java.lang" Object o)
Return the index of the first occurrence of o in this list or -1 if this list does not contain o.
ArrayList cities = new ArrayList( );
cities.add( "Baltimore" );
// more statements adding cities to the ArrayList cities
Use indexOf to retrieve the index of the city New York in cities (it may or may not be there) and assign the result to a variable of your choice.