Java LinkedHashSet MCQ Questions and Answers

Q. What is the default sorting order of keys in a TreeMap?

A. Ascending order
B. Descending order
C. No specific order
D. Depends on the data type of keys
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Q. Which interface does TreeMap implement?

A. Map
B. SortedMap
C. NavigableMap
D. All of the above
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Q. What is the output of the following code snippet?

TreeMap<String, Integer> map = new TreeMap<>();

    map.put("C", 3);

    map.put("A", 1);

    map.put("B", 2);

    System.out.println(map.firstKey());

A. A
B. B
C. C
D. None of the above
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Q. How can you iterate over the keys in a TreeMap in ascending order?

A. Using an iterator obtained from the keySet() method
B. Using a for-each loop directly on the TreeMap
C. Using the values() method and iterating over the values
D. None of the above
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(3, "C");

    map.put(1, "A");

    map.put(2, "B");

    System.out.println(map.higherKey(2));

A. 2
B. 3
C. null
D. None of the above
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.remove(2);

    System.out.println(map.get(2));

A. A
B. B
C. C
D. null
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(3, "C");

    map.put(1, "A");

    map.put(2, "B");

    System.out.println(map.pollFirstEntry());

A. (1, A)
B. (2, B)
C. (3, C)
D. None of the above
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.descendingMap();

    System.out.println(map.firstKey());

A. 1
B. 3
C. null
D. None of the above
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.put(4, "D");

    System.out.println(map.subMap(2, 4).firstKey());

A. 1
B. 2
C. 3
D. 4
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.put(4, "D");

    System.out.println(map.headMap(3).lastKey());

A. 1
B. 2
C. 3
D. None of the above
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.put(4, "D");

    System.out.println(map.tailMap(2).firstKey());

A. 1
B. 2
C. 3
D. 4
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.put(4, "D");

    System.out.println(map.containsKey(2));

A. true
B. false
C. null
D. An error occurs
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Q. What is the output of the following code snippet?

TreeMap<Integer, String> map = new TreeMap<>();

    map.put(1, "A");

    map.put(2, "B");

    map.put(3, "C");

    map.put(4, "D");

    System.out.println(map.containsValue("B"));

A. true
B. false
C. null
D. An error occurs
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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);
treeMap.put("Apple", 10);

System.out.println(treeMap.get("Apple"));

A.

5

B.

10

C.

null

D.

Exception: Duplicate key "Apple"

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Q. How can you iterate through the keys and values of a TreeMap in ascending order?

A.

for (Map.Entry<String, Integer> entry : treeMap.entrySet()) {
    String key = entry.getKey();
    int value = entry.getValue();
    // Process key and value
}

B.

for (String key : treeMap.keySet()) {
    int value = treeMap.get(key);
    // Process key and value
}

C.

for (int value : treeMap.values()) {
    String key = treeMap.getKey(value);
    // Process key and value
}

D.

Iterator<Map.Entry<String, Integer>> iterator = treeMap.entrySet().iterator();
while (iterator.hasNext()) {
    Map.Entry<String, Integer> entry = iterator.next();
    String key = entry.getKey();
    int value = entry.getValue();
    // Process key and value
}

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.firstKey());
System.out.println(treeMap.lastKey());

A.

Apple
Cherry

B.

Banana
Cherry

C.

Apple
Banana

D.

Banana
Apple

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

treeMap.remove("Banana");

System.out.println(treeMap);

A.

{Apple=5, Cherry=8}

B.

{Apple=5}

C.

{Banana=3, Cherry=8}

D.

{}

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.lowerKey("Banana"));

A.

Apple

B.

Banana

C.

Cherry

D.

null

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.higherKey("Banana"));

A.

Apple

B.

Banana

C.

Cherry

D.

null

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.subMap("Apple", "Cherry"));

A.

{Apple=5, Banana=3}

B.

{Apple=5, Banana=3, Cherry=8}

C.

{Banana=3, Cherry=8}

D.

{Apple=5, Cherry=8}

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.headMap("Banana"));

A.

{Apple=5}

B.

{Apple=5, Banana=3}

C.

{Banana=3}

D.

{Apple=5, Banana=3, Cherry=8}

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.tailMap("Banana"));

A.

{Banana=3, Cherry=8}

B.

{Apple=5, Banana=3}

C.

{Apple=5, Banana=3, Cherry=8}

D.

{Banana=3}

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Q. What will be the output of the following code?

TreeMap<String, Integer> treeMap = new TreeMap<>();
treeMap.put("Apple", 5);
treeMap.put("Banana", 3);
treeMap.put("Cherry", 8);

System.out.println(treeMap.containsKey("Mango"));

A.

true

B.

false

C.

Exception: Key not found

D.

null

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