3i Infotech Placement: Sample Questions 496 - 497 of 1245
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Question 496
Statement True-False▾
Final variables should be declared in the beginning?
Choices
Choice (4) | |
---|---|
a. | True |
b. | False |
c. | All of the above |
d. | None of the above |
Answer
a.Explanation
- True, final prevents modification of variable, but those have to be initialized at some point- constructor is the right place.
- Value of a final variable can only be set once- constructor can guarantee this.
- Constructor is called once for an object while other methods can be called any number of times.
- A “blank final” instance variable of a class must be definitely assigned at the end of every constructor of the class in which it is declared.
- A “blank final static” variable must be definitely assigned in a static initializer of the class.
Question 497
Explanation
- Common lisp and few other languages support multiple inheritance while java does not support.
- Java does not allow multiple inheritances to avoid the ambiguity caused by it.
- One of the examples of problem is the diamond problem that occurs in multiple inheritances.
- Moreover, concrete classes have the option to implement multiple interface using single class.
- Multiple interface inheritance allows an object to inherit many different method signatures with the caveat that the inheriting object must implement inherited methods.