Last Updated : 11 Jul, 2025
The remove() method of the Java HashMap class is used to remove a key-value pair from the map based on the given key. If the key is found, the mapping associated with the key is returned, otherwise, it returns null.
Example 1: This example demonstrates how to use remove(Object key) to remove a key-value pair based on the key.
Java
// Java program to demonstrate the
// remove(Object key) method
import java.util.HashMap;
public class Geeks {
public static void main(String[] args) {
// Creating a HashMap
HashMap<Integer, String> hm1 = new HashMap<>();
// Adding elements
hm1.put(1, "Java");
hm1.put(2, "C++");
hm1.put(3, "Python");
System.out.println("Original HashMap: " + hm1);
// Removing an element
String r = hm1.remove(2);
// Displaying removed value and
// HashMap after removal
System.out.println("Removed Value: " + r);
System.out.println("HashMap after removal: " + hm1);
}
}
Original HashMap: {1=Java, 2=C++, 3=Python}
Removed Value: C++
HashMap after removal: {1=Java, 3=Python}
Syntax of HashMap remove() Method
There are two Syntax of remove() which are listed below:
// Removes the key-value pair for the specified key
V remove(Object key)// Removes the key-value pair if the key exists and the value matches exactly
boolean remove(Object key, Object value)
Parameters:
Return Types:
Example 2: This example demonstrates the use of remove(Object key, Object value) method removes a key-value pair only if both matches exaclty.
Java
// Java program to demonstrates the
// working of remove(Object key, Object value)
import java.util.HashMap;
public class Geeks {
public static void main(String[] args)
{
HashMap<Integer, String> hm = new HashMap<>();
// Adding elements to the HashMap
hm.put(1, "Java");
hm.put(2, "C++");
hm.put(3, "Python");
System.out.println("Original HashMap: " + hm);
// trying to remove key-value pair (2, "C++")
boolean r1 = hm.remove(2, "C++");
System.out.println("Was the pair (2, C++) removed? "
+ r1);
System.out.println("HashMap after removal: " + hm);
// trying to remove key-value
// pair (3,"JavaScript")
boolean r2 = hm.remove(3, "JavaScript");
System.out.println(
"Was the pair (3, JavaScript) removed? " + r2);
System.out.println("HashMap after second attempt: "
+ hm);
}
}
Output:
Example 3: This example demonstrates the use of remove(Object key) method to remove key-value pairs and handle non-exisiting keys and null values.
Java
// Java program to demonstrates remove(Object key)
import java.util.HashMap;
public class Geeks {
public static void main(String[] args)
{
// Create a HashMap with Integer
// keys and String values
HashMap<Integer, String> hm = new HashMap<>();
// Add some key-value pairs
hm.put(1, "Java");
hm.put(2, "C++");
hm.put(3, null);
// Remove key 2 and print
// the returned value
String r = hm.remove(2);
System.out.println("Removed Value for key 2: " + r);
// Try removing a non-existent key
String n = hm.remove(4);
System.out.println(
"Removed Value for non-existent key 4: " + n);
// Remove key 3 (value was explicitly set to null)
String nullValue = hm.remove(3);
System.out.println("Removed Value for key 3: "
+ nullValue);
}
}
Removed Value for key 2: C++ Removed Value for non-existent key 4: null Removed Value for key 3: null
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