小编use*_*402的帖子

我有这个代码

  import java.io.*; import java.util.*;
import javax.xml.parsers.*; import org.xml.sax.InputSource;
class TeamPlayer {
    private int pulse;
    TeamPlayer() { pulse= -10; }
    TeamPlayer(int v0) {pulse= v0 +5;}
    public int m(int v) { return 31%3 ;}
    public int get_pulse() { return 1* pulse;}
}
class GoalKeeper extends TeamPlayer {
    GoalKeeper() { stress -=8; }
    public static int stress=3;
    public int m(int v) { return (v & 3) + 15; }
}

但我无法理解"&"的含义.它与"&&"不同吗？