Proszę o podpowiedź dlaczego wykonanie kodu powoduje:
run:
true Exception in thread "main" java.lang.NullPointerException at new2015_01_21.MyBoolean. myMethod(MyBoolean.java:20) at new2015_01_21.MyBoolean.main(MyBoolean.java:15) Java Result: 1 BUILD SUCCESSFUL (total time: 0 seconds)
KOD:
class MyBoolean { Boolean bool[] = new Boolean[5]; // 10 public static void main(String[] args) { Boolean [] bool = {true, true, false, true, false}; // 13 System.out.println(bool[1]); // 14 new MyBoolean().myMethod(); // 15 System.out.println(bool[1]); } public void myMethod() { if (bool[1] == true) { // 20 System.out.println("It's true"); } else { System.out.println("It's false"); } } }