Challenges

Remember the rules for this are

Try to use only the information given up to this point in this book.
Try not to give up until you've given it a solid attempt

Challenge 1.

Write a file named hello.txt and give it Hello, world as contents.

Challenge 2.

Write a program that asks the user for a number and writes it into a file named numbers.txt.

Challenge 3.

Update the previous program so that the list of numbers entered by a user is stored in the file. So if they give 1, 2, and 3 the file should contain something like the following.

1
2
3

Hint: \n is how you embed a newline character in String. You might find it useful.

Challenge 4.

Update the previous program to also display the biggest number given so far if the user types biggest instead of a number.

Challenge 5.

Make the previous program behave sensibly if the file contains data that is not numbers.

Challenge 6.

Complete this program.

import java.nio.file.Path;
import java.io.IOException;

class Main {
    record Person(String name, int age) {}

    void main() throws IOException {
        var people = new Person[] {
            new Person("Steve Smith", 15),
            new Person("Stan Smith", 42),
            new Person("Rodger", 1601)
        };

        var path = Path.of("people.txt");

        save(path, people);

        people = load(path);

        System.out.println(people[0]);
        System.out.println(people[1]);
        System.out.println(people[2]);

    }

    void save(Path path, Person[] people) throws IOException {
        // Save to a file
    }

    Person[] load(Path path) throws IOException {
        return null; // Make actually return an array
    }
}

Modern Java