CODEWITHSUNDEEP
javanetbeans
Emmanuel Adeniji
Emmanuel Adeniji

Reputation: 31

Type Set does not take parameters

package set;

import java.util.*;

public class Set 
{

  public static void main(String[] args)
  {
    String [] things = {"appple", "bob", "ham", "bob", "bacon"};
    List<String> list = Arrays.asList(things);

    System.out.printf("%s ", list);
    System.out.println();

    Set<String> set = new HashSet<String>(list);
    System.out.printf("%s ", set);

  }

}

When I try to run this program I keep getting this error for my set declaration. What am I doing wrong?

Upvotes: 3

Views: 3343

Answers (4)

Ankur Singhal
Ankur Singhal

Reputation: 26077

Though not a good idea to name the classes that are already present in Java API etc.

Adding this will be enough

java.util.Set<String> set = new HashSet<String>(list);

Still you make some change to the existing

package set;

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;

public class Set {

    public static void main(String[] args) {
        String[] things = { "appple", "bob", "ham", "bob", "bacon" };
        List<String> list = Arrays.asList(things);

        System.out.printf("%s ", list);
        System.out.println();

        java.util.Set<String> set = new HashSet<String>(list);
        System.out.printf("%s ", set);

    }
}

Upvotes: 0

Elliott Frisch
Elliott Frisch

Reputation: 201497

You have shadowed the java.util.Set import by naming your own local class Set (set.Set has a higher scope visibility and isn't generic). You could rename set.Set, or use the fully qualified name (and the diamond operator <>). Change

Set<String> set = new HashSet<String>(list);

to something like

java.util.Set<String> set = new HashSet<>(list);

Upvotes: 0

Jesper
Jesper

Reputation: 206926

You named your own class Set, hiding the standard class Set in package java.util.

Rename your class to something else than Set.

Upvotes: 1

Eran
Eran

Reputation: 393966

Rename your public class Set class to a name that doesn't hide java.util.Set.

Your custom Set class doesn't take any type parameters. That's why Set<String> doesn't pass compilation.

For example:

package set;

import java.util.*;

public class SetTest 
{
    public static void main(String[] args)
    {
        String [] things = {"appple", "bob", "ham", "bob", "bacon"};
        List<String> list = Arrays.asList(things);

        System.out.printf("%s ", list);
        System.out.println();

        Set<String> set = new HashSet<String>(list);
        System.out.printf("%s ", set);  
    } 
}

Upvotes: 3

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