java 8 iterating and manipulating list

In Java 8 and later, you can use the Stream API to iterate over the elements of a List and perform operations on them.

To iterate over the elements of a List and perform operations on them, you can use the map method of the Stream interface to apply a function to each element of the List, and the forEach method to perform an action on each element of the List.

Here is an example of how you can use the map and forEach methods to iterate over the elements of a List and manipulate them:

import java.util.List;
import java.util.Arrays;

public class MyClass {
    public static void main(String[] args) {
        List<String> words = Arrays.asList("apple", "banana", "cherry");

        // Convert the words to uppercase
        words.stream()
            .map(String::toUpperCase)
            .forEach(System.out::println); // Outputs "APPLE", "BANANA", "CHERRY"

        // Add a prefix to each word
        words.stream()
            .map(s -> "PREFIX: " + s)
            .forEach(System.out::println); // Outputs "PREFIX: apple", "PREFIX: banana", "PREFIX: cherry"
    }
}

In this example, the wordsList contains three strings: "apple", "banana", and "cherry".

The first map operation applies the toUpperCase method to each element of the List, and the forEach operation prints the uppercase versions of the words to the console.