Question

I have a class called MatchingLine

    public class MatchingLine implements Comparable
     {
        private String matchingLine;
        private int numberOfMatches;

        // constructor...
        // getters and setters...
        // interface method implementation...
     }

I am using this class in an ArrayList as follows –

    ArrayList<MatchingLine> matchingLines = new ArrayList<MatchingLine>();

However, the Netbeans IDE puts a note beside this statement and says,

   redundant type arguments in new expression (use diamond operator instead)

and it suggests that I use –

    ArrayList<MatchingLine> matchingLines = new ArrayList<>();

I always thought the former style was the convention? Is the latter style the convention?

Answer 1

ArrayList<MatchingLine> matchingLines = new ArrayList<>();

This is a new feature in Java 7 called diamond operator.