Java Hashmap forEach() Method
What is a Hashmap?
Hashmap class is a part of java.util package. In Java everything is based on classes and objects. hashmap key/value pairs can be stored , but no duplicate key is allowed.If a duplicate key is inserted it will replace the present value with the new value. Many built-in methods are there in hashmap class which makes it easy to perform operations on them, like insertion , deletion and many more. One of those methods is Java Hashmap forEach() Method.
To know more about Hashmap forEach() Method read the complete article.
Java Hashmap forEach() Method
The hashmap forEach() method is used to make a change or perform a action on each pair of key/value present in the hashmap. Below in this page you can find it’s syntax, return values, parameters with detailed examples.
Syntax :
new_hashmap.forEach(biConsumer(K,V) Action);
Return values :
This method does not returns any values.
Hashmap forEach() Method Example
Example :
import java.util.*;
public class Main
{
public static void main (String[]args)
{
// Creating an empty HashMap
HashMap < String, Integer > hash_map_1 =
new HashMap < String, Integer > ();
// Mapping string values to int keys in a empty hashmap
hash_map_1.put ("Java", 10);
hash_map_1.put ("Hashmap", 20);
hash_map_1.put ("forEach", 30);
hash_map_1.put ("Method", 40);
System.out.println ("Original hashmap : " + hash_map_1);
hash_map_1.forEach ((key, value)->
{
value = value * value;
System.out.println ("Key : " + key + " , value : " + value);
}
);
}
}
Output :
Original hashmap : {Java=10, Hashmap=20, forEach=30, Method=40}
Key : Java , value : 100
Key : Hashmap , value : 400
Key : forEach , value : 900
Key : Method , value : 1600
Now hashmap forEach() method is used to square the value mapped to each key and print the key and value.
Prime Course Trailer
Related Banners
Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription
Get over 200+ course One Subscription
Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others
