Java Objects and Classes MCQ - Multiple Choice Questions And Answers

Q. What is an object in Java?

A. It is a programming construct that represents a real-world entity
B. It is a data type
C. It is a collection of variables and methods
D. All of the above
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Q. What is a class in Java?

A. It is a programming construct that represents a real-world entity
B. It is a data type
C. It is a collection of variables and methods
D. All of the above
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Q. What is encapsulation in Java?

A. It is a programming construct that represents a real-world entity
B. It is a data type
C. It is a mechanism of wrapping data and code together into a single unit
D. All of the above
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Q. Which keyword is used to create an object in Java?

A. new
B. Object
C. create
D. instance
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Q. What is a constructor in Java?

A. It is a method of a class
B. It is used to create objects of a class
C. It has the same name as the class
D. All of the above
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Q. What is inheritance in Java?

A. It is a way to create objects of a class
B. It is a mechanism of reusing code
C. It allows a class to inherit properties and behaviors from another class
D. All of the above
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Q. What is a method in Java?

A. It is a programming construct that represents a real-world entity
B. It is a data type
C. It is a collection of variables and methods
D. It is a block of code that performs a specific task
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Q. What is method overriding in Java?

A. It is a mechanism of reusing code
B. It allows a subclass to provide a different implementation of a method defined in its superclass
C. It is a way to create objects of a class
D. All of the above
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Q. What is the purpose of the Predicate functional interface in Java 8?

A. To produce results
B. To consume values
C. To filter elements based on a condition
D. To transform values
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Q. What is the purpose of the toString() method in Java?

A. To convert an object to a string representation
B. To get the hash code of an object
C. To compare two objects for equality
D. None of the above
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Q. What is an object in Java?

A. A function that belongs to a class.
B. A variable that belongs to a class.
C. An instance of a class.
D. A method that belongs to a class.
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Q. Which of the following is true about a constructor in Java?

A. It is used to create a new object.
B. It is a member function of a class.
C. It has the same name as the class.
D. All of the above.
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Q. What is the purpose of the 'new' keyword in Java?

A. To create a new class.
B. To create a new object.
C. To create a new method.
D. To create a new variable.
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Q. What is encapsulation in Java?

A. A way to hide the internal implementation of an object.
B. A way to access the internal implementation of an object.
C. A way to inherit the properties of an object.
D. A way to define the properties of an object.
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Q. Which keyword is used to refer to the superclass in Java?

A. this
B. super
C. parent
D. base
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Q. What is method overriding in Java?

A. Defining a method with the same name but different parameters in the same class.
B. Defining a method with the same name and same parameters in the same class.
C. Defining a method with the same name but different parameters in a subclass.
D. Defining a method with the same name and same parameters in a subclass.
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Q. What is method overloading in Java?

A. Defining a method with the same name but different parameters in the same class.
B. Defining a method with the same name and same parameters in the same class.
C. Defining a method with the same name but different parameters in a subclass.
D. Defining a method with the same name and same parameters in a subclass.
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Q. What is the output of the following code snippet?

public class MyClass {
    int x = 5;

    public static void main(String[] args) {
        MyClass myObj = new MyClass();
        System.out.println(myObj.x);
    }
}

A. 0
B. 1
C. 5
D. Error
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Q. Which of the following is true about static variables in Java?

A. They are shared by all instances of a class.
B. They can be accessed using the class name.
C. They are initialized only once, when the class is loaded.
D. All of the above.
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