### programming languages Online Quiz - 75

 Description: programming languages Online Quiz - 75 Number of Questions: 20 Created by: Aliensbrain Bot Tags: programming languages
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System.out.format("Pi is approximately %d.", Math.PI); What is the result?

1. Compilation fails

2. Pi is approximately 3

3. Pi is approximately 3.141593

4. An exception is thrown at runtime

Correct Option: D

#### AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Compilation fails - This option is incorrect. The code will compile successfully as there are no syntax errors.

Option B) Pi is approximately 3 - This option is incorrect. The code uses the format specifier `%d`, which is used for integer values. Since `Math.PI` is a double value, using `%d` will result in incorrect output.

Option C) Pi is approximately 3.141593 - This option is incorrect. Although the output format is correct for a double value, the precision is not specified. The default precision for `double` is usually 6, so the output will be rounded to 3.141593.

Option D) An exception is thrown at runtime - This option is correct. The code uses the format specifier `%d` for an integer value, but `Math.PI` returns a double value. When trying to format the double value with `%d`, an exception will be thrown at runtime.

The correct answer is D. An exception is thrown at runtime because the format specifier `%d` is not compatible with the double value `Math.PI`.

NumberFormat nf = NumberFormat.getInstance(); nf.setMaximumFractionDigits(4); nf.setMinimumFractionDigits(2); String a = nf.format(3.1415926); String b = nf.format(2); Which statement is true about the result?

1. The value of b is 2

2. The value of b is 2.00

3. The value of a is 3.141

4. The value of a is 3.1415

Correct Option: B

public class Yippee2 { static public void main(String [] yahoo) { for(int x = 1; x < yahoo.length; x++) { System.out.print(yahoo[x] + " "); } } } and the command line invocation: java Yippee2 a b c What is the result?

1. a b

2. b c

3. a b c

4. Compilation fails

Correct Option: B

public static void main(String[] args) { String str = "null"; if (str == null) { System.out.println("null"); } else (str.length() == 0) { System.out.println("zero"); } else { System.out.println("some"); } } What is the result?

1. null

2. zero

3. some

4. Compilation fails

Correct Option: D

SELECT address1||','||address2||','||address2 "Adress" FROM employee;

1. 1

2. 2

3. 3

4. 0

Correct Option: C

#### AI Explanation

To answer this question, let's analyze the given SQL query:

``````SELECT address1||','||address2||','||address2 "Adress" FROM employee;
``````

This query is selecting the concatenation of the `address1`, `address2`, and `address2` columns from the `employee` table, separated by commas. The result is being aliased as "Address".

Now let's go through each option to determine the correct answer:

Option A) 1 - This option is incorrect because the query does not output the value 1.

Option B) 2 - This option is incorrect because the query does not output the value 2.

Option C) 3 - This option is correct. The query concatenates the values of `address1`, `address2`, and `address2` columns with commas in between, and aliases it as "Address".

Option D) 0 - This option is incorrect because the query does not output the value 0.

Therefore, the correct answer is C) 3.

Which of the following languages can be used to write server side scripting in ASP.NET?

1. c#

2. VB

3. C++

4. A & B

Correct Option: D

When an .aspx page is requested from the web server, the out put will be rendered to browser in following format.

1. HTML

2. XML

3. WML

4. JSP

Correct Option: A

To add a custom control to a Web form we have to register with.

1. TagPrefix

2. Name space of the dll that is referenced

3. Assemblyname

4. All of the above

Correct Option: D

#### AI Explanation

To add a custom control to a Web form, we need to register it with certain information. Let's go through each option to understand why it is correct or incorrect:

Option A) TagPrefix - This option is correct. When adding a custom control to a Web form, we typically use a TagPrefix to associate a prefix with the custom control. This prefix is used in the markup of the Web form to indicate that the control belongs to a specific namespace or assembly.

Option B) Namespace of the DLL that is referenced - This option is correct. When adding a custom control to a Web form, we need to reference the DLL that contains the control's code. The namespace of the DLL is important because it is used to identify the control and specify its location in the code.

Option C) Assemblyname - This option is correct. When adding a custom control to a Web form, we need to specify the assembly name of the DLL that contains the control's code. This is necessary for the Web form to locate and use the custom control.

Option D) All of the above - This option is correct. All of the options A, B, and C are required to successfully add a custom control to a Web form. We need to specify the TagPrefix, the namespace of the DLL, and the assembly name to properly register and use the custom control.

Therefore, the correct answer is D) All of the above. This option is correct because all the options mentioned (TagPrefix, namespace of the DLL, and assembly name) are required to register a custom control with a Web form.

What's the difference between Response.Write() andResponse.Output.Write()?

1. Response.Output.Write() allows you to flush output

2. Response.Output.Write() allows you to buffer output

3. Response.Output.Write() allows you to write formatted output

4. Response.Output.Write() allows you to stream output

Correct Option: C

The number of forms that can be added to a aspx page is.

1. 1

2. 2

3. 3

4. more than 3

Correct Option: A

How do you manage states in asp.net application

1. Session object

2. Application object

3. View state

4. All of the above

Correct Option: D

What is the program design method we learned in order to write Object Oriented Programs?

1. Declare - Define - Use

2. Public functions and private variables

3. Top - Down programming

4. Bottom - Up programming

Correct Option: C

Which is a logical abstract base class for a class called "footballPlayer"?

1. Salary

2. Sport

3. Athlete

4. Team

Correct Option: C

#### AI Explanation

To answer this question, we need to understand the concept of logical abstract base classes. A logical abstract base class represents a broader category or concept that other classes can inherit from.

Let's go through each option to understand why it is correct or incorrect:

Option A) Salary - This option is incorrect because "Salary" is not a logical abstract base class for a "footballPlayer". "Salary" represents a specific attribute or property of a football player, rather than a broader category or concept.

Option B) Sport - This option is incorrect because "Sport" is also not a logical abstract base class for a "footballPlayer". "Sport" represents a broader category that includes various sports, including football. However, it does not specifically represent a category that a "footballPlayer" would inherit from.

Option C) Athlete - This option is correct because "Athlete" is a logical abstract base class for a "footballPlayer". An athlete can participate in various sports, including football. By inheriting from the "Athlete" class, the "footballPlayer" class can inherit common attributes and behaviors associated with being an athlete.

Option D) Team - This option is incorrect because "Team" is not a logical abstract base class for a "footballPlayer". "Team" represents a specific entity or group that a football player can be a part of, rather than a broader category or concept.

The correct answer is C) Athlete. This option is correct because "Athlete" represents a logical abstract base class for a "footballPlayer".

A recursive function would result in infinite recursion, if the following were left out:

1. Base case

2. Recursive call

3. Subtraction

4. Local variable declarations

Correct Option: C

#### AI Explanation

To answer this question, we need to understand the concept of recursion in programming.

Recursion is a programming technique where a function calls itself to solve a problem by breaking it down into smaller subproblems.

In order for a recursive function to work correctly, it requires three essential components:

A. Base case: A base case is a condition that is used to terminate the recursion. It is the simplest form of the problem that does not require further recursive calls. Without a base case, the recursive function would continue calling itself infinitely, resulting in infinite recursion.

B. Recursive call: The recursive call is the step where the function calls itself with a smaller or simpler version of the problem. This allows the function to break down the original problem into smaller subproblems. Without the recursive call, the function would not be able to solve the problem recursively.

C. Subtraction: While subtraction is often used in recursive functions, it is not a requirement for a recursive function to work correctly. Recursive functions can perform various operations depending on the problem at hand, such as addition, multiplication, or string manipulation. The specific operation used in a recursive function depends on the problem being solved.

D. Local variable declarations: Local variable declarations are not required for a recursive function to work correctly. Recursive functions can use local variables to store intermediate results or perform calculations, but they are not essential for the recursion itself.

Based on the above explanations, the correct answer is C. If subtraction were left out, the recursive function could still work correctly as long as it includes a base case and recursive call.

Can two classes contain member functions with the same name?

1. No

2. Yes, but only if the two classes have the same name

3. Yes, but only if the main program does not declare both kinds

4. Yes, this is always allowed

Correct Option: D

A derived class

1. Inherits data members and member functions from base class

2. Inherits constructors and destructor

3. Object can access protected members with the dot operator

4. Inherits data members and member functions from base class as well as Inherits constructors and destructor

Correct Option: D

_________is a relationship

1. Polymorphism

2. Inheritance

3. Overloading

4. None of these options

Correct Option: B

Abstract class cannot have ________?

1. Zero instance

2. Multiple instance

3. Both Zero instance & Multiple instance

4. None of these options

Correct Option: C

#### AI Explanation

To answer this question, we need to understand the concept of abstract classes in object-oriented programming.

An abstract class is a class that cannot be instantiated on its own and serves as a blueprint for other classes to inherit from. It is used to define common attributes and methods that will be shared by its subclasses.

Option A) Zero instance - This option is correct. An abstract class cannot have zero instances because it cannot be instantiated on its own. It can only be used as a base class for other classes.

Option B) Multiple instances - This option is incorrect. An abstract class can have multiple instances through its concrete subclasses. The concrete subclasses can be instantiated and used to create multiple objects.

Option C) Both Zero instance & Multiple instances - This option is incorrect. An abstract class cannot have zero instances, but it can have multiple instances through its concrete subclasses.

Option D) None of these options - This option is incorrect. The correct answer is option C.

Therefore, the correct answer is C) Both Zero instance & Multiple instance.

Maintaining the state of an object is called____?

1. Serialization

2. Persistence

3. Marshalling

4. None of these options

Correct Option: B
Explanation:

To solve this question, the user needs to understand the concept of object-oriented programming and the terminology used in it.

The state of an object refers to the values of its attributes or properties at a given point in time. Maintaining the state of an object means preserving these values so that they can be used later, even after the program has ended.

Now, let's go through each option and explain why it is right or wrong:

A. Serialization: Serialization refers to the process of converting an object into a format that can be stored or transmitted. While serialization can be used to maintain the state of an object, it is not the same thing as maintaining the state.

B. Persistence: This option is correct. Persistence refers to the act of preserving data beyond the lifetime of a program. In the context of object-oriented programming, persistence means maintaining the state of an object so that it can be used again later.

C. Marshalling: Marshalling is a technique used to transfer data between different applications or systems. While marshalling can be used to preserve the state of an object during transfer, it is not the same thing as maintaining the state.

D. None of these options: This option is incorrect because option B, Persistence, is the correct answer.

Therefore, The Answer is: B. Persistence.

______ means that both the data and the methods which may access it are defined together in the same unit.

1. Data hiding

2. Encapsulation

3. Data Binding

4. None of these options

Correct Option: B

#### AI Explanation

To answer this question, you need to understand the concept of encapsulation.

Encapsulation refers to the practice of combining data and the methods that operate on that data into a single unit or class. This unit is known as an object in object-oriented programming.

Option A) Data hiding - Data hiding is a concept related to encapsulation, where the internal representation of an object is hidden from the outside world. While data hiding is a part of encapsulation, it is not the complete definition of encapsulation.

Option B) Encapsulation - This option is correct. Encapsulation is the process of combining data and the methods that operate on that data into a single unit or class.

Option C) Data Binding - Data binding is a concept that establishes a connection between the application UI and the data it displays. It is not directly related to encapsulation.

Option D) None of these options - This option is incorrect, as the correct answer is option B) Encapsulation.

The correct answer is B) Encapsulation. This option is correct because it accurately describes the concept of combining data and methods in the same unit or class.

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