HashMap Class

This lesson provides some more detail on the built-in methods of the Hashmap class in Java.

We'll cover the following


A HashMap stores items in “key/value” pairs, and you can access them by an index of another type. A HashMap can store different types, including, String keys and Integer values.

It contains the following methods:

put() - Used to add keys and values.

get(key) - To access a value in the HashMap using its key.

clear() - To remove all mappings.

containsKey(key) - Returns true if one or more key is mapped to a specified value. 

isEmpty() - Returns true if the map contains no key-value mappings.

size() - Returns the number of key-value mappings in the map.

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