Map put() Method in Java with Examples

The map java interface is present in java.util package is used to represent a mapping between a key and a value.Map put() method is used to associate the specified value with the specified key in the map.

Syntax: 

V put(K key, V value)

Parameters: This method has two arguments, key and value where the key is the left argument and the value is the corresponding value of the key in the map.  

Return Value: This method returns the previous value associated with the key if present, else returns a null value. 

To know more about what is map java refers to article Map Java interface.

The below programs show the implementation of the int put() method. 

Example 1:

Java

// Java code to show the implementation of
// put method in Map interface
import java.util.*;
public class GfG {

    // Driver code
    public static void main(String[] args)
    {

        // Initializing a Map of type HashMap
        Map<Integer, String> map = new HashMap<>();
        map.put(1, "One");
        map.put(3, "Three");
        map.put(5, "Five");
        map.put(7, "Seven");
        map.put(9, "Nine");
        System.out.println(map);
    }
}

Output

{1=One, 3=Three, 5=Five, 7=Seven, 9=Nine}

Example 2: Below is the code to show the implementation of put(). 

Java

// Java code to show the implementation of
// put method in Map interface
import java.util.*;
public class GfG {

    // Driver code
    public static void main(String[] args)
    {

        // Initializing a Map of type HashMap
        Map<String, String> map = new HashMap<>();
        map.put("1", "One");
        map.put("3", "Three");
        map.put("5", "Five");
        map.put("7", "Seven");
        map.put("9", "Nine");
        System.out.println(map);
    }
}

Output

{1=One, 3=Three, 5=Five, 7=Seven, 9=Nine}