Practice Map Interface (15.5.1) - Collections and Generics

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9 questions

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Exercise
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Quiz
3 questions · about 2 min · pass mark 70%. Hints available.
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6 sample questions

Question 1.
What does the put method do in a Map?
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Think about how you would add an item to a list.
Question 2.
True or False: A Map can have duplicate keys.
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Consider if you can have two identical names in a contact list.
3Question 3.
Which of the following methods adds a key-value pair to a Map?
- get()
- put()
- remove()
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Consider which option sounds like it relates to 'adding'.
4Question 4.
True or False: A TreeMap automatically sorts keys.
- True
- False
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Think about how trees grow: do they follow an order?
Question 5.
Create a method that counts the number of occurrences of each character in a string. Use a HashMap for this solution.
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Think about how you can check if a character already exists in your Map.
Question 6.
Implement a contact manager using a LinkedHashMap where you can add, find, and update contacts based on unique names.
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Consider what happens when you want to look for a name: does order matter?

5 more questions in this section. Enroll free to practise them all.