Java | Class and Object | Question 1

Predict the output of following Java program?

class Test {
  int i;
}
class Main {
   public static void main(String args[]) {
     Test t;
     System.out.println(t.i);
}

(A) 0
(B) garbage value
(C) compiler error
(D) runtime error

Answer: (C)
Explanation: t is just a reference, the object referred by t is not allocated any memory. Unlike C++, in Java all non-primitive objects must be explicitly allocated and these objects are allocated on heap. The following is corrected program.

class Test {
  int i;
}
class Main {
   public static void main(String args[]) {
     Test t = new Test();
     System.out.println(t.i);
}

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