我是新來的Java和我在處理對象數組時遇到了問題。我的主要程序是這樣的:NullPointerException當創建OBJECT ARRAYS和使用它們
package bicycledemo;
class BicycleDemo {
public static void main(String[] args) {
// Create two different
// Bicycle objects with an array
Bicycle[] bike = new Bicycle[2];
bike[0].cadence=50; //line 10, where the NullPointerException prompts out
bike[0].gear=2;
bike[1].cadence=10;
bike[1].gear=3;
System.out.println("gear: "+bike[0].gear+"\n"+"cadence: "+bike[0].cadence+"\n");
System.out.println("gear: "+bike[1].gear+"\n"+"cadence: "+bike[1].cadence+"\n");
System.out.println("\b");
}
}
和自行車類是這個:
package bicycledemo;
public class Bicycle {
public Bicycle() {
}
public int cadence;
public int gear;
}
當我運行該程序,輸出錯誤是:
Exception in thread "main" java.lang.NullPointerException
at bicycledemo.BicycleDemo.main(BicycleDemo.java:10)
Java Result: 1
我想,發生什麼事是對象自行車沒有正確創建,但我不明白爲什麼。
非常感謝您的幫助!我非常渴望解決這個問題!
@TedHopp:不,代碼真的*看起來沒什麼問題。 – 2013-02-24 18:27:21