java 8 map foreach

In Java 8 and later, you can use the forEach method of the Map interface to iterate over the key-value pairs of a Map and perform an action on each pair.

To use the forEach method to iterate over the key-value pairs of a Map, you can use the following syntax:

map.forEach((key, value) -> {
    // code to be executed for each key-value pair
});

Here, map is the name of the Map, key is a variable that represents the current key being iterated over, and value is a variable that represents the current value being iterated over.

Here is an example of how you can use the forEach method to iterate over the key-value pairs of a Map and print them to the console:

import java.util.Map;
import java.util.HashMap;

public class MyClass {
    public static void main(String[] args) {
        Map<String, Integer> map = new HashMap<>();
        map.put("apple", 1);
        map.put("banana", 2);
        map.put("cherry", 3);

        map.forEach((key, value) -> System.out.println(key + ": " + value));
        // Outputs "apple: 1", "banana: 2", "cherry: 3"
    }
}

It is important to note that the forEach method does not return a value, and it cannot be used to modify the elements of the Map. If you need to modify the elements of the Map, you can use a traditional for loop with an iterator, or you can use the replaceAll method of the Map interface.