我在这个 for 循环示例中遇到了困难

Question

The method evenSquares takes a single int parameter, n, (for example, 10000), and then prints all of the (positive) even perfect squares less than n, each on a separate line.

Notice that evenSquares has a void return type, since all it does is print integers to the console. Be sure to use the println method to print each entry of your output.

Example: if n = 40, your code should print:

4
16
36

(Hint: your method should be built around a for loop with a test component that asks if the square of the control variable (say, k) is < n. Thus, the loop should terminate as soon as k*k equals or exceeds n.)

I'm given this

public void evenSquares(int n) {

Answer 1

public class Squares {

    public static void main(String[] args) {        
        evenSquares(40);
    }

    public static void evenSquares(int n) {
        for(int sq, k=2; (sq = k*k) <= n ; k += 2){
            System.out.println(sq);
        }
    }

}