Java Online Quiz
Following quiz provides Multiple Choice Questions (MCQs) related to Core Java. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.
Answer : B
Explaination
Boolean is a class and is not a keyword.
Answer : D
Explaination
The long data type is represented by 64-bit two's complement integer.
Minimum value: -263
Maximum value: 263-1
Answer : A
Explianation
Byte variable has default value of 0 if defined as an instance/static variable.
Q 4 - Which of the following is true about public access modifier?
A - Variables, methods and constructors which are declared public can be accessed by any class.
Answer : A
Explaination
Public access modifier is used to make variables, methods and constructors accessible to any class.
Q 5 - What is Abstraction?
A - Abstraction is a technique to define different methods of same type.
B - Abstraction is the ability of an object to take on many forms.
C - It refers to the ability to make a class abstract in OOP.
Answer : C
Explaination
It refers to the ability to make a class abstract in OOP. It helps to reduce the complexity and also improves the maintainability of the system.
Q 6 - What is an applet?
A - An applet is a Java program that runs in a Web browser.
Answer : A
Explaination
An applet is a Java program that runs in a Web browser.
Q 7 - Static binding uses which information for binding?
Answer : A
Explaination
Static binding uses type information for binding.
Q 8 - What are Wrapper classes?
A - These are classes that allow primitive types to be accessed as objects.
B - These are classes that wraps functionality of an existing class.
Answer : A
Explaination
These are classes that allow primitive types to be accessed as objects. Example: Integer, Character, Double, Boolean etc.
Q 9 - What will happen if static modifier is removed from the signature of the main method?
B - RunTime Error: NoSuchMethodError.
C - Program will compile and run without any output.
D - Program will compile and run to show the required output.
Answer : B
Explaination
Program throws "NoSuchMethodError" error at runtime.
Q 10 - Which of the following is a thread safe?
Answer : B
Explaination
StringBuffer is thread safe.
