1. What is VBScript?
VBScript is a scripting language developed by Microsoft that is used for creating dynamic websites and web applications.

2. How do you declare variables in VBScript?
In VBScript, you don’t need to declare variables explicitly. Variables are created and assigned values on the fly.

3. What is the difference between Dim and Set in VBScript?
The “Dim” statement is used to declare variables, while the “Set” statement is used to assign an object reference to a variable.

4. What are the different variable types in VBScript?
VBScript supports different variable types such as String, Integer, Boolean, Date, Double, Object, etc.

5. How do you concatenate strings in VBScript?
In VBScript, you can concatenate strings using the “&” operator. For example: “Hello ” & “World” will result in “Hello World”.

6. How do you write comments in VBScript?
In VBScript, you can write comments using the single quotation mark (‘) at the beginning of a line. Anything after the quotation mark is treated as a comment.

7. How do you perform arithmetic operations in VBScript?
VBScript supports arithmetic operations such as addition (+), subtraction (-), multiplication (*), division (/), and modulus (%).

8. How do you read command line arguments in VBScript?
You can read command line arguments in VBScript using the “WScript.Arguments” collection. For example, “WScript.Arguments(0)” refers to the first argument passed.

9. How do you create a function in VBScript?
To create a function in VBScript, use the “Function” keyword followed by the function name, parameters (if any), and the code block enclosed in “End Function”.

10. How do you call a function in VBScript?
To call a function in VBScript, use the function name followed by parentheses and arguments (if any). For example, “myFunction(arg1, arg2)”.

11. How do you handle errors in VBScript?
You can handle errors in VBScript using the “On Error Resume Next” statement to suppress errors and the “Err” object to get the error number and description.

12. How do you convert a string to uppercase in VBScript?
You can convert a string to uppercase in VBScript using the “UCase” function. For example, “UCase(“hello”)” will result in “HELLO”.

13. How do you get the current date and time in VBScript?
You can get the current date and time in VBScript using the “Now” function. For example, “Now()” will return the current date and time.

14. How do you loop through an array in VBScript?
You can loop through an array in VBScript using a “For Each” loop. For example,

    arr = Array("apple", "banana", "orange")
    For Each item In arr
        WScript.Echo item
    Next

15. How do you get the length of a string in VBScript?
You can get the length of a string in VBScript using the “Len” function. For example, “Len(“hello”)” will return 5.

16. How do you convert a string to a number in VBScript?
You can convert a string to a number in VBScript using the “CInt”, “CDbl”, or “CDec” functions, depending on the desired numeric type.

17. How do you exit a loop in VBScript?
You can exit a loop in VBScript using the “Exit Do” statement for a “Do” loop or the “Exit For” statement for a “For” loop.

18. How do you create and manipulate file objects in VBScript?
You can create and manipulate file objects in VBScript using the “FileSystemObject” object and its methods like “CreateTextFile” and “OpenTextFile”.

19. How do you write to a text file in VBScript?
You can write to a text file in VBScript using the “WriteLine” or “Write” methods of the “TextStream” object.

20. How do you handle user input in VBScript?
You can handle user input in VBScript using the “InputBox” function to display a prompt and receive user input, or by using command-line arguments to read input from the command line.

1. What are the different types of variables available in VBScript?
In VBScript, there are four types of variables:
– Explicit: Variables whose type is explicitly defined using Dim or Set keyword.
– Implicit: Variables whose type is determined based on the assigned value.
– Variant: Variables that can hold any type of data.
– Object: Variables used to store object references.

2. How do you declare a constant in VBScript?
To declare a constant in VBScript, use the Const keyword followed by the name of the constant, the equal sign (=), and the value. For example:
“`vbscript
Const PI = 3.14
“`

3. Explain the difference between ByRef and ByVal in VBScript.
ByRef and ByVal are used in function or procedure calls to pass arguments. ByRef passes the memory reference of an argument, so any changes made to the argument within the function will affect the original value. ByVal, on the other hand, passes a copy of the value, so changes made within the function won’t affect the original value.

4. What is the purpose of Option Explicit in VBScript?
Option Explicit is a statement used to force explicit declaration of all variables in VBScript. It ensures that all variables are declared before use, helping to avoid typographical errors and to improve code quality.

5. How do you handle errors in VBScript?
VBScript provides an On Error statement to handle runtime errors. This statement allows you to specify how the script should behave when an error occurs. There are different error handling modes, such as On Error Resume Next and On Error Goto 0, to control the error handling behavior.

6. Explain the difference between functions and subroutines in VBScript.
Functions and subroutines both help in code organization and reusability. The main difference is that functions return a value, while subroutines do not. Functions are called using their name and assigned to a variable if a return value is expected, whereas subroutines are called by their name alone.

7. What are the different types of loops available in VBScript?
VBScript supports three types of loops:
– For Loop: Executes a block of code for a specific number of times.
– While Loop: Executes a block of code as long as the specified condition is true.
– Do…Loop: Executes a block of code until a specified condition is false.

8. How can you read and write data to text files in VBScript?
VBScript provides the FileSystemObject (FSO) to read from and write to text files. By creating an instance of FSO, you can use its methods, such as OpenTextFile, ReadLine, WriteLine, etc., to achieve file handling operations.

9. Explain the concept of recursion in VBScript.
Recursion is a technique where a function calls itself repeatedly until a certain condition is met. This allows for solving problems that can be divided into smaller sub-problems. However, recursive functions should be used with caution, as they can consume a lot of memory and lead to stack overflow errors if not implemented properly.

10. How do you create and handle COM objects in VBScript?
To create and handle COM objects in VBScript, you can use the CreateObject function. This function creates an instance of a COM object, which can then be accessed and manipulated using its properties and methods.

11. What is the purpose of the Err object in VBScript?
The Err object in VBScript is used to store information about runtime errors that occur during script execution. It provides properties such as Err.Number, Err.Description, and Err.Source to access error details and handle them accordingly.

12. Explain the usage of the Execute and ExecuteGlobal functions in VBScript.
The Execute and ExecuteGlobal functions in VBScript are used to execute a block of code stored as a string. Execute executes the code within the local scope, while ExecuteGlobal executes the code in the global scope. These functions are commonly used for dynamic code execution or code stored in variables.

13. How can you access environment variables in VBScript?
VBScript provides the WScript.Shell object’s ExpandEnvironmentStrings method to access environment variables. This method takes an environment variable name as input and returns its value.

14. Explain the difference between single-quoted (”) and double-quoted (“”) strings in VBScript.
In VBScript, both single-quoted and double-quoted strings are used to define string literals. The main difference is that double-quoted strings support escape sequences and variable interpolation, while single-quoted strings do not. For example, “Hello, ” & name concatenates the variable name with the double-quoted string.

15. How can you use regular expressions in VBScript?
VBScript provides the RegExp object to work with regular expressions. By creating an instance of RegExp, you can use its methods (e.g., .Pattern, .Execute, .Replace) for pattern matching and string manipulation.

16. How do you handle type conversion in VBScript?
VBScript provides a set of built-in functions to convert variable types, such as CInt, CDbl, CStr, etc. These functions allow you to convert variables from one data type to another based on your requirements.

17. How can you debug VBScript code?
You can debug VBScript code using the MsgBox function or the WScript.Echo method to print variable values or debugging messages. Additionally, tools like Microsoft Script Debugger or third-party IDEs provide more comprehensive debugging capabilities.

18. Explain the usage of the Execute, Eval, and ExecuteGlobal functions in VBScript.
– Execute: Executes statements within the local scope.
– Eval: Evaluates an expression and returns the result.
– ExecuteGlobal: Executes statements within the global scope.

19. What is the purpose of IsEmpty function in VBScript?
The IsEmpty function in VBScript is used to check if a variable is uninitialized or does not contain a value. It returns True if the variable is empty, and False otherwise.

20. What is late binding in VBScript?
Late binding in VBScript refers to creating object references without specifying the object type at compile-time. Instead, the object type is determined dynamically at runtime. This allows for more flexibility but may result in a slower execution speed.