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.
Q 1 - What is a class in java?
B - class is a special data type.
Answer : A
Explaination
A class is a blue print from which individual objects are created. A class can contain fields and methods to describe the behavior of an object.
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
Explaination
char variable has default value of '\u0000' if defined as an instance/static variable.
Q 4 - Which of the following is true about protected access modifier?
A - Variables, methods and constructors which are declared protected can be accessed by any class.
Answer : B
Explaination
Variables, methods, and constructors which are declared protected can be accessed by any class lying in the same package.
Answer : B
Explaination
It is not mandatory to have a default constructor in a class.
Q 6 - What is JRE?
A - JRE is a java based GUI application.
B - JRE is an application development framework.
C - JRE is an implementation of the Java Virtual Machine which executes Java programs.
Answer : C
Explaination
Java Runtime Environment is an implementation of the Java Virtual Machine which executes Java programs. It provides the minimum requirements for executing a Java application.
Q 7 - What is function overloading?
A - Methods with same name but different parameters.
B - Methods with same name but different return types.
C - Methods with same name, same parameter types but different parameter names.
Answer : A
Explaination
If a class has multiple functions by same name but different parameters, it is known as Method Overloading.
Q 8 - What happens when thread's yield() method is called?
A - Thread returns to the ready state.
Answer : A
Explaination
When a task invokes its yield() method, it returns to the ready state.
Q 9 - What is runtime polymorphism?
Answer : A
Explaination
Runtime polymorphism or dynamic method dispatch is a process in which a call to an overridden method is resolved at runtime rather than at compile-time. In this process, an overridden method is called through the reference variable of a superclass.
Answer : A
Explaination
Postfix operators i.e () [] . is at the highest precedence.
