Java HashMap forEach() Method

Java HashMap

The forEach() method is used to perform a specified action on each mapping in the HashMap.

The syntax for the forEach() method is:

hashmap.forEach(BiConsumer&lt;K, V> action)

Note: hashmap is an object of the HashMap class.

Parameter Description:

action - The action to be performed

Return Value

It does not return any value.

Example

The following example demonstrates the use of the forEach() method:

Example

import java.util.HashMap;

class Main {
    public static void main(String[] args) {
        // Create a HashMap
        HashMap&lt;String, Integer> prices = new HashMap<>();

        // Insert mappings into the HashMap
        prices.put("Shoes", 200);
        prices.put("Bag", 300);
        prices.put("Pant", 150);
        System.out.println("Normal Price: " + prices);

        System.out.print("Discounted Price: ");

        // Use forEach() with a lambda expression
        prices.forEach((key, value) -> {
            // Reduce the price by 10%
            value = value - value * 10/100;
            System.out.print(key + "=" + value + " ");
        });
    }
}

Executing the above program outputs:

Normal Price: {Pant=150, Bag=300, Shoes=200}
Discounted Price: Pant=135 Bag=270 Shoes=180

Note this line:

prices.forEach((key, value) -> {
    // Reduce the price by 10%
    value = value - value * 10/100;
    System.out.print(key + "=" + value + " ");
});

In the above example, we pass an anonymous function lambda expression as a parameter to the forEach() method. The lambda expression reduces each element in the dynamic array by 10% and then outputs the result.

For more information on lambda expressions, visit Java Lambda Expressions.

Note: The forEach() method is different from the for-each loop. Java for-each is used to iterate over each element in an array.

Java HashMap

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