HashMap put(K, V) in Java

put(K, V): This method is available in java.util.HashMap class of Java.

Syntax:

V java.util.HashMap.put(K key, V value)

This method takes two arguments. This method associates the specified value with the specified key in this map.

Note: If the map previously contained a mapping for the key, the old value is replaced.

Parameters: Two parameters are required for this method.

key: key with which the specified value is to be associated.

value: value to be associated with the specified key

Returns: the previous value associated with key, or null if there was no mapping for key.

Exceptions: NA

Approach

Java

import java.util.HashMap;

public class HashMapput {
    public static void main(String[] args) {
        HashMap<String, Integer> hashMap = 
                     new HashMap<String, Integer>();

        hashMap.put("Hello", 1);
        hashMap.put("World", 2);

        System.out.println(hashMap);

    }
}

Output:

{Hello=1, World=2}