Sets Review

Front

Which of the following statement about Set is true? A TreeSet can have null values. Set allows duplicate values. Set allows null values but only single occurrence. Set extends the Java.util.collection interface.

Back

Set extends the Java.util.collection interface.

Front

Entries are not organized as key/value pairs. Duplicate entries are rejected. Which interface of the java.util package offers the specified behavior?

Back

Set

Front

Back

[Computer, Network, Networks, Programming, Security]

Front

Back

Line 11 : Genetates NullPointer Exception

Front

What is the output of the following code?
List listNames = new ArrayList();
listNames.add("Tom");
listNames.add("Mary");
listNames.add("Peter");
String name2 = (String) listNames.get(1);
System.out.println(name2);

Back

Mary

Front

When do we use sets in java program?

Back

You want to store elements distinctly without duplication, or unique elements.

Front

What will happen if an element already present in the Set is added again?

Back

A boolean value of false will be returned, and the value will not be added to the Set

Front

Which of the following Set methods will add a key to a Set? Options: add(), remove(), set(), get(), indexOf()

Back

add()

Front

Which of the following HashSet instantiations would create a HashSet that could store Strings? Options: HashSet<Double> set = new HashSet<Double>();, HashSet<Integer> set = new HashSet<Integer>();, HashSet<String> set = new HashSet<String>();, HashSet<Boolean> set = new HashSet<Boolean>();, HashSet<Byte> set= new HashSet<Byte>();

Back

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

Front

Which of the following is an interface? ArrayLIst, HashSet, TreeMap, Collection, LinkedList

Back

Collection