Counting in a loop

To count something in a loop, create a counter before the loop, starting at 0, and add one to it inside the loop each time the thing happens. After the loop, the counter holds the total.

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int count = 0;
        while (true) {
            String word = scanner.nextLine();
            if (word.equals("end")) {
                break;
            }
            count++;
        }
        System.out.println("Words: " + count);
    }
}

apple
pear
plum
end

Words: 3

count++ is Java's shorthand for count = count + 1. There's also count--, which takes one away.

Where the counter goes

The counter must be created before the loop. Created inside it, it would start again from 0 in every round, and it could never count past 1. The first challenge has exactly this mistake.