如何將NullPointerException
併入以下push()
Java中的堆棧方法?Java中Stack的push()方法中的NullPointerException
public void push(E e) {
int len = size();
if (len == 0)
throw new NullPointerException();
else
addElement(e);
System.out.println("The element pushed is " + e);
}
在PSVM,每當我調用push()
方法它給出了不添加到堆棧中的空指針異常。
public static void main(String[] args) {
try {
SortableStack<Object> s = new SortableStack<Object>();
s.push(10);
s.push(20);
System.out.println("The element popped is " + s.pop());
}
catch (NullPointerException e) {
System.out.println("Null Pointer Exception encountered!");
}
}
非常感謝!工作順利,快捷! –
不客氣! :) – Behrang
@Zeeshan,不要忘記標記答案爲[「Accepted」](http://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work/5235#5235 ) –