[問題] && 和 &

[unknown]

public class ShortCircuit {

public static void main(String[] args) {
String s=null;
if((s != null) && s.length() > 20)
System.out.println(s);

String t=null;
if((t != null) & t.length() > 20)
System.out.println(t);
}
}

如題,第一個if不會印出東西,(短路運算子)

第二個if為什麼會有NullPointerException呢?

謝謝回應


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 stack.push(life.running); | the complier will
 stack.push(scouting.buck()); | answer your life
 stack.push(bowling.pratice()); | Bone everything

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