TCS Core Java Questions - Quiz

Q: What will be the output?

public class Test{
	static{
		int a = 5;
	}

	public static void main(String args[]){
		new Test().call();
	}

	void call(){
		this.a++;
		System.out.print(this.a);
	}
}

A. Compile with error
B. Runtime Exception
C. 5
D. 6

Correct Option: A
Remarks:

Explanation: Compile with error

Q: What will be the output of the following program code?


class Rectangle{
      public int area(int length, int width){
            return  length*width;
      }
}
class Square extends Rectangle{
      public int area(long length, long width){
            return  (int) Math.pow(length, 2);
      }
}
public class Test{
      public static void main(String args[]){
            Square r = new Square();
            System.out.println(r.area(5 , 4));
      }
}

A. Will not compile.
B. Will compile and run printing out 20
C. Runtime error
D. Will compile and run printing out 25

Correct Option: B
Remarks:

Explanation: Will compile and run printing out 20

Q: Java allows you to control access to classes, methods, and fields via specifiers.

A. control
B. java
C. access
D. standard

Correct Option: C
Remarks:

Explanation:

The correct option is:

access

Java uses access specifiers (also known as access modifiers) to control the visibility of classes, methods, and fields. These include public, private, protected, and the default (package-private) access level.

Q: The _____ keyword basically says to the JVM "Warning, this variable may be modified in another Thread".

A. this
B. super
C. new
D. volatile

Correct Option: D
Remarks:

Explanation:

The correct option is:

volatile

In Java, the volatile keyword tells the JVM that a variable's value may be modified by multiple threads, ensuring that the most up-to-date value of the variable is always read by the threads.

Q: ________ interface needs to be implemented for making object copies.

A. cut
B. set
C. cloneable
D. carbon

Correct Option: C
Remarks:

Explanation:

The correct option is:

cloneable

The Cloneable interface needs to be implemented in a class to allow objects to be copied (cloned) using the clone() method in Java.

Q: Iterators are a generic way to go through all the elements of a ______ no matter how it is organized.

A. liststack
B. container
C. array
D. collection

Correct Option: D
Remarks:

Explanation:

The correct option is:

collection

Iterators provide a generic way to traverse through all the elements of a collection (such as lists, sets, etc.) regardless of how the elements are organized.

Q: Java uses ______ data types and hence is not a pure OOP.

A. built in, dynamic
B. static
C. primitive
D. standard

Correct Option: C
Remarks:

Explanation:

The correct option is:

primitive

Java uses primitive data types (such as int, char, boolean, etc.), which are not objects. This is why Java is not considered a pure object-oriented programming language.

Q: Overriding can be used when we need to overide the method of superclass from_____class.

A. sub
B. main, dervided
C. local
D. global

Correct Option: A
Remarks:

Explanation:

The correct option is:

sub

Overriding occurs when a method in a subclass has the same name and parameters as a method in its superclass, allowing the subclass to provide a specific implementation of that method.

Q: The Conditional operator are called as_____.

A. Singleton operator, Binary operator
B. Secondary Operator
C. Primary operator
D. Ternary Operator

Correct Option: D
Remarks:

Explanation:

The correct option is:

Ternary Operator

The ternary operator in Java is a conditional operator that takes three operands and is used as a shorthand for an if-else statement. Its syntax is: condition ? expression1 : expression2.

Q: The _______ keyword is used to declare an interface.

A. int, inter
B. static
C. interface
D. this

Correct Option: C
Remarks:

Explanation:

The correct option is:

interface

The interface keyword is used in Java to declare an interface.

TCS Core Java Questions - Quiz

What will be the output? public class Test{ static{ int a = 5; } public static void main(String args[]){ new Test().call(); } void call(){ this.a++; System.out.print(this.a); } }

Java allows you to control access to classes, methods, and fields via specifiers.

The _____ keyword basically says to the JVM "Warning, this variable may be modified in another Thread".

________ interface needs to be implemented for making object copies.

Iterators are a generic way to go through all the elements of a ______ no matter how it is organized.

Java uses ______ data types and hence is not a pure OOP.

Overriding can be used when we need to overide the method of superclass from_____class.

The Conditional operator are called as_____.

The _______ keyword is used to declare an interface.

What will be the output?
public class Test{ static{ int a = 5; } public static void main(String args[]){ new Test().call(); } void call(){ this.a++; System.out.print(this.a); } }