Read Lines

Reading a file as lines makes each record available for a loop.

ReadLines.java

import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

public class ReadLines {
    public static void main(String[] args) throws Exception {
        int bonus = ;
        Path path = Path.of("java21_lines.txt");
        Files.write(path, List.of("3", "4", String.valueOf(bonus)));

        List<String> lines = Files.readAllLines(path);
        int sum = 0;
        for (String line : lines) {
            sum += Integer.parseInt(line);
        }

        Files.deleteIfExists(path);
        System.out.println("lines=" + lines.size() + " sum=" + sum);
    }
}

import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

public class ReadLines {
    public static void main(String[] args) throws Exception {
        int bonus = ;
        Path path = Path.of("java21_lines.txt");
        Files.write(path, List.of("3", "4", String.valueOf(bonus)));

        List<String> lines = Files.readAllLines(path);
        int sum = 0;
        for (String line : lines) {
            sum += Integer.parseInt(line);
        }

        Files.deleteIfExists(path);
        System.out.println("lines=" + lines.size() + " sum=" + sum);
    }
}

import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

public class ReadLines {
    public static void main(String[] args) throws Exception {
        int bonus = ;
        Path path = Path.of("java21_lines.txt");
        Files.write(path, List.of("3", "4", String.valueOf(bonus)));

        List<String> lines = Files.readAllLines(path);
        int sum = 0;
        for (String line : lines) {
            sum += Integer.parseInt(line);
        }

        Files.deleteIfExists(path);
        System.out.println("lines=" + lines.size() + " sum=" + sum);
    }
}

line list Files.readAllLines returns a List where each element is one line from the file.

parse loop A parse loop converts text records into the numeric values the program needs.