2024's Top 20 Perl Interview Questions: Expert Answers

Let us start by answering the same question again: Why Perl? Why is it a much-needed scripting language for most of the developers and programmers out there? 

Because, by borrowing features from other programming languages, including C, shell script, AWK, and sed, Perl has proven itself to be one of the most sophisticated and fine-shaped programming languages! How?

Because it provides text processing facilities without the arbitrary data length limits of many contemporary Unix command-line tools, it facilitates the manipulation of text files. Perl 5 gained widespread popularity in the late 1990s as a CGI scripting language, in part due to its unsurpassed regular expression and string parsing abilities.

So learning Perl is so important in today’s world to crack an interview.

Well, enough of these jibber jabber. Let’s get into the top 20 Perl interview questions now. Shall we?

Top 20 Perl Interview Questions

1. Explain what the Perl language is.

Answer:  The full form of PERL is “Practical Extraction and Reporting Language”. Perl is a powerful scripting language that is rich in features and helps you write powerful and efficient code for mission-critical projects.

2. What are the various advantages and disadvantages of Perl?

Answer: A few advantages of Perl are:

• It is user-friendly and efficient 
• Perl program can be interpreted on a statement-by-statement basis.
• It is portable and platform-independent.
• Various open-source packages and modules can be included in a Perl program for any additional functionality.

The main disadvantages of Perl are:

• Its slow execution speed is quite slow
• One can’t write complex code using Perl. 
• Perl has too many features that can be exhaustive for a programmer.

3. What are the various uses of Perl?

Answer: Few usages of Perl  are:

• In a mission-critical project
• "Rapid Prototyping”

4. Explain the various characteristics of Perl.

Answer: The characteristics of Perl are mentioned below:

• Case-sensitive
• Easy to code
• Open-source
• Portable and cross-platform.
• Extendable
• There is no distinction between the types of variables.
• It Can return non-linear types 
• Non-scalars can be used as loop indices in Perl
• Supports high-level intrinsic operations 
• Allows powerful text manipulation API including Regular expressions

5. Explain the execution of a program in Perl.

Answer: Because of being portable, we can execute Perl programs on any platform. Programmers can even write the Perl code on a notepad and then execute the program using the command prompt.

6. What are the various flags and arguments that can be used while executing a Perl program?

Answer: You can use the following arguments while executing a Perl program:.

• w – argument shows a warning.
• d – used for debugging.
• c – compiles only do not run.
• e – execute.

7. Comment on data types and variables in Perl.

Answer: Variables in Perl don’t usually have a data type. The data type of a variable in Perl can be inferred from its value.

Before using a variable, the value needs to be assigned to it. If it is not assigned, the program may result in an unexpected output.

8. What are Scalars in Perl?

Answer: Scalars are the variables in Perl that have values with linear data types like integer, float, or string.

9. Comment on the scope of variables in Perl.

Answer: All the variables in Perl are global in scope by default. This means that a variable can be used as a reminder of the program from the point where it has been declared.

10. What are Numeric Operators in Perl?

Answer: Numeric operators in Perl are:

• Arithmetic operators (+,-,*/).
• Comparison operators to compare two numbers (>, <, ==, !=,<=,>=,<=>).
• Bitwise Operators(&(and), |(or),^(ex-or),~(not),<<(shift left),>>(shift right)).

11. What are the different string manipulation operators in Perl?

Answer: Perl usually provides two different operators to manipulate strings.

• Concatenation Operator (.)
• Repetition Operator (x)

12. What is chomp() operator or function?

Answer: chomp() operator helps in removing the last character of a string and returns the number of characters removed. It becomes useful while reading input data from the console to remove a newline (\n) character.

13. Differentiate between Arrays and List in Perl.

Answer: Both a list and an array are sets of elements. The main difference between a list and an array in Perl is that a list is immutable and cannot be altered directly.  An array, on the other hand, is mutable, and its contents can grow or even shrink in size.

14. Explain Arrays in Perl.

Answer: Arrays in Perl are only used to contain scalar elements. Arrays are not allowed to contain another array and its element.

Arrays in Perl somewhat looks like this:

@myarray = (1,4,5);

15. Differences between DIE and EXIT.

Answer: DIE function in Perl exits the program and prints a specified message.  On the other hand, Exit simply exits the program.

16. What is a subroutine in Perl?

Answer: Subroutine is a block of code in Perl that can be reused by a program either internally or externally.

17. How to open a file in Perl?

“open” library function is used to open a file. It works as follows:

open(filevar,filename);

where filevar=> like a file pointer used by Perl to refer a file

filename=>location of the file to be opened.

open(filevar,>filename);

When the file needs to be opened in the ‘Append’ mode, we need to precede the filename with ‘>>’ characters.

open(filevar, >>filename);

‘open’ function returns a non-zero value when the file is opened successfully. If it’s not successfully opened, it returns zero.

18. How to read from a file in Perl?

Once a file has been opened, we can read data line-by-line from the file with the help of this following code:

$line = <filevar>;

19. How do I write or append to a file in Perl?

We can write data to a file using the following code:

Print filevar(“This is to be written to file\n”)

Conclusion:

Did we drive away your interview fear regarding Perl questions with these? No? Well, if not, you can ask away your queries in the comment section below anytime you want. Also, don’t forget to check out our courses once, those ones that can help you add extra colors to your wings of Perls!

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