Java HashMap Exercises, Practice & Solutions

Java Collection: HashMap Exercises [12 exercises with solution]

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HashMap:

In Java, HashMap is an implementation of the Map interface provided by the Java Collections Framework. It's part of the java.util package.

1. Write a Java program to associate the specified value with the specified key in a HashMap.
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2. Write a Java program to count the number of key-value (size) mappings in a map.
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3. Write a Java program to copy all mappings from the specified map to another map.
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4. Write a Java program to remove all mappings from a map.
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5. Write a Java program to check whether a map contains key-value mappings (empty) or not.
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6. Write a Java program to get a shallow copy of a HashMap instance.
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7. Write a Java program to test if a map contains a mapping for the specified key.
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8. Write a Java program to test if a map contains a mapping for the specified value.
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9. Write a Java program to create a set view of the mappings contained in a map.
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10. Write a Java program to get the value of a specified key in a map.
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11. Write a Java program to get a set view of the keys contained in this map.
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12. Write a Java program to get a collection view of the values contained in this map.
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