i don't understand this method haw it work !!!?

[hamza]

private char encryptChar(char c, int k) {
    	if (Character.isLetter(c))
    		return (char) ('A' + (c - 'A' + k) % 26);
    	else
    		return c;
    }

[Rabbit]

It's basically a caeser cipher. Meaning that it shifts a character k number of characters forward. With k = 1, a becomes b, b becomes c, c becomes d, z becomes a, etc.