Map collection is used to store key-value pairs. Here is how to use it: Create a Map: Use Map
map = new HashMap<>(). Add elements: use map.put("key", "value"). Get elements: use String value = map.get("key"). Check for the existence of a key: use map.containsKey("key"). Remove elements: use map.remove("key"). Go over
Map collection in Java: usage method
Map collection is a powerful data structure in Java , used to store key-value pairs. It allows users to quickly retrieve values using keys. Here's how to use a Map collection in Java:
To create a Map collection, you can use the following syntax:
Map<K, V> map = new HashMap<>();
Where:
To add elements to the Map collection, you can use the put() method:
map.put("key", "value");
To get the value in the Map collection, you can use the get() method:
String value = map.get("key");
To check whether a key exists in the Map collection, you can use the containsKey() method:
boolean containsKey = map.containsKey("key");
To delete elements from the Map collection, you can use the remove() method:
map.remove("key");
To traverse the elements of the Map collection, you can use the entrySet() method. It returns a Set containing all key-value pairs in the Map collection:
for (Map.Entry<K, V> entry : map.entrySet()) { K key = entry.getKey(); V value = entry.getValue(); }
Common implementation class of Map collection
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