PERL Interview Questions and Answers, PERL Interview Questions and Answers Freshers, PERL Interview Questions and Answers, PERL Interview Questions
Before getting on to the PERL interview questions, the student must know that the PERL is a continuously varying field which needs the students as well as professionals to upgrade their skills with the new features and knowledge, to get fit for the jobs associated with PERL. This post related to PERL Interview Questions and Answers, PERL Interview Questions and Answers Freshers, PERL Interview Questions and Answers, PERL Interview Questions will help you let out find all the solutions that are frequently asked in you upcoming PERL interview.
Over thousands of vacancies available for the PERL developers, experts must be acquaintance with all the component of PERL technologies. This is necessary for the students in order to have in-depth knowledge of the subject so that they can have best employment opportunities in the future. Knowing every little detail about PERL is the best approach to solve the problems linked with problem.
APTRON has spent hours and hours in researching about the PERL Interview Questions and Answers, PERL Interview Questions and Answers Freshers, PERL Interview Questions and Answers, PERL Interview Questions that you might encounter in your upcoming interview. All these questions will alone help you to crack the interview and make you the best among all your competitors.
First of all, let us tell you about how the PERL technology is evolving in today’s world and how demanding it is in the upcoming years. In fact, according to one study, most of the companies and businesses have moved to the PERL. Now, you cannot predict how huge the future is going to be for the people experienced in the related technologies.
Hence, if you are looking for boosting up your profile and securing your future, PERL will help you in reaching the zenith of your career. Apart from this, you would also have a lot of opportunities as a fresher.
These questions alone are omnipotent. Read and re-read the questions and their solutions to get accustomed to what you will be asked in the interview. These PERL interview questions and answers will also help you on your way to mastering the skills and will take you to the giant world where worldwide and local businesses, huge or medium, are picking up the best and quality PERL professionals.
This ultimate list of best PERL interview questions will ride you through the quick knowledge of the subject and topics like PERL Database, Managing the Database Instance, Administering User Security, Managing Undo Data. This PERL interview questions and answers can be your next gateway to your next job as a PERL expert.
These are very Basic PERL Interview Questions and Answers for freshers and experienced both.
Q1: Difference between the variables in which chomp function work ?
A1: Scalar: It is denoted by $ symbol. Variable can be a number or a string.
Array: Denoted by @ symbol prefix. Arrays are indexed by numbers.
The namespace for these types of variables is different. For Example: @add, $add. The scalar variables are in one table of names or namespace and it can hold single specific information at a time and array variables are in another table of names or namespace. Scalar variables can be either a number or a string
Q2: In Perl we can show the warnings using some options in order to reduce or avoid the errors. What are that options?
A2: -The -w Command-line option: It will display the list if warning messages regarding the code.
– strict pragma: It forces the user to declare all variables before they can be used using the my() function.
– Using the built-in debugger: It allows the user to scroll through the entire program line by line.
Q3: Does Perl have objects? If yes, then does it force you to use objects? If no, then why?
A3: Yes, Perl has objects and it doesn’t force you to use objects. Many object oriented modules can be used without understanding objects. But if the program is too large then it is efficient for the programmer to make it object oriented.
Q4: Which guidelines by Perl modules must be followed?
A4: Below are guidelines and are not mandatory
The name of the package should always begin with a capital letter.
The entire file name should have the extension “.pm”.
In case no object oriented technique is used the package should be derived from the Exporter class.
Also if no object oriented techniques are used the module should export its functions and variables to the main namespace using the @EXPORT and @EXPOR_OK arrays (the use directive is used to load the modules).
Q5: What do you mean by context of a subroutine?
A5: It is defined as the type of return value that is expected. You can use a single function that returns different values.
Q6: In CPAN module, name an instance you use.
A6: In CPAN, the CGI and DBI are very common packages
Q7: What are the advantages of cover Perl?
A7: There are more development tools for C than for PERL. PERL execute slower than C programs. Perl appears to be an interpreted language but the code is complied on the fly. If you don’t want others to use your Perl code you need to hide your code somehow unlike in C. Without additional tools it is impossible to create an executable of a Perl program
Q8: Mention the difference between die and exit in Perl?
A8: Die will print a message to the std err before ending the program while Exit will simply end up the program.
Q9: What does -> symbol indicates in Perl?
A9: In Perl, the arrow – > symbol is used to create or access a particular object of a class.
Q10: Mention what is CPAN?
A10: CPAN means Comprehensive Perl Archive Network, a large collection of Perl software and documentation.
Q11: Can we load binary extension dynamically?
A11: Yes, we can load binary extension dynamically but your system supports that. If it doesn’t support, then you can statically compile the extension.
Q12: 9.How do I replace every TAB character in a file with a comma?
A12: perl -pi.bak -e ‘s/\t/,/g’ myfile.txt
Q13: How many types of primary data structures in Perl and what do they mean?
A13: The scalar: It can hold one specific piece of information at a time (string, integer, or reference). It starts with dollar $ sign followed by the Perl identifier and Perl identifier can contain alphanumeric and underscores. It is not allowed to start with a digit. Arrays are simply a list of scalar variables.
Arrays: Arrays begin with @ sign. Example of array:
my @arrayvar = (“string a”, “string b “string c”);
Associative arrays: It also frequently called hashes, are the third major data type in Perl after scalars and arrays. Hashes are named as such because they work very similarly to a common data structure that programmers use in other languages–hash tables. However, hashes in Perl are actually a direct language supported data type.
Q14: How the interpreter is used in Perl?
A14: Every Perl program must be passed through the Perl interpreter in order to execute. The first line in many Perl programs is something like:
#!/usr/bin/perl
The interpreter compiles the program internally into a parse tree. Any words, spaces, or marks after a pound symbol will be ignored by the program interpreter. After converting into parse tree, interpreter executes it immediately. Perl is commonly known as an interpreted language, is not strictly true. Since the interpreter actually does convert the program into byte code before executing it, it is sometimes called an interpreter/compiler. Although the compiled form is not stored as a file.
Q15: For a situation in programming, how can you determine that Perl is a suitable?
A15: If you need faster execution the Perl will provide you that requirement. There a lot of flexibility in programming if you want to develop a web based application. We do not need to buy the license for Perl because it is free. We can use CPAN (Comprehensive Perl Archive Network), which is one of the largest repositories of free code in the world.
Q16: How will you declare a variable in perl?
A16: Perl variables do not have to be explicitly declared to reserve memory space. The declaration happens automatically when you assign a value to a variable. The equal sign (=) is used to assign values to variables.
Q17: What is boolean context?
A17: Boolean context is simply any place where an expression is being evaluated to see whether it’s true or false.
Q18: What is V-Strings?
A18: A literal of the form v1.20.300.4000 is parsed as a string composed of characters with the specified ordinals. This form is known as v-strings.
A v-string provides an alternative and more readable way to construct strings, rather than use the somewhat less readable interpolation form “\x{1}\x{14}\x{12c}\x{fa0}”.
Q19: What is the purpose of _PACKAGE_ literal?
A19: It is used to get the current package name.
Q20: What is the purpose of redo statement?
A20: The redo command restarts the loop block without evaluating the conditional again. The continue block, if any, is not executed.
Q21: What is the purpose of goto Expr statement?
A21: The goto EXPR form is just a generalization of goto LABEL. It expects the expression to return a label name and then jumps to that labeled statement.
Q22: How will you get the count of parameters passed to a perl subroutine?
A22: using scalar(@_), we can get the total number of arguments passed.
Q23: How would you ensure the re-use and maximum readability of your Perl code?
A23: modularize code and include them where required using the “use” command
use subroutines or functions to segregate operations thereby making the code more readable
use objects to create programs wherever possible which greatly promotes code reuse
include appropriate comments as and when required
eliminate any dereferencing operator
Q24: What is the importance of Perl warnings? How do you turn them on?
A24: Warnings are one of the most basic ways in which you can get Perl to check the quality of the code that you have produced. Mandatory warnings highlight problems in the lexical analysis stage. Optional warnings highlight cases of possible anomaly.
The traditional way of enabling warnings was to use the -w argument on the command line:
perl -w myscript.pl
You can also supply the option within the “shebang” line:
#/usr/local/bin/perl -w
You can also mention use warnings with all, deprecated and unsafe options.
Eg: use warnings ‘all’;
Q25: What is the use of command “use strict”?
A25: Use strict command calls the strict pragma and is used to force checks on definition and usage of variables, references and other barewords used in the script. If unsafe or ambiguous statements are used, this command stops the execution of the script instead of just providing warnings.
Q26: Explain: a.) Lists b.) iValue
A26: a.) Lists
Lists are special type of arrays that hold a series of values. Lists can either be explicitly generated by the user using a paranthesis and comma to separate the values or can be a value returned by a function when evaluated in list context.
b.) iValue
An ivalue is a scalar value that can be used to store the result of any expression. Ivalues appear in the left hand side of the expression and usually represents a data space in memory.
Q27: Explain different types of Perl Operators.
A27:
-Arithmetic operators, +, – ,* etc
-Assignment operators: += , -+, *= etc
-Increment/ decrement operators: ++, —
-String concatenation: ‘.’ operator
-comparison operators: ==, !=, >, < , >= etc
-Logical operators: &&, ||, !
Q28: How Does A “grep” Function Perform?
A28: Grep returns the number of lines the expression is true. Grep returns a sub list of a list for which a specific criterion is true. This function often involves pattern matching. It modifies the elements in the original list.
Q29: Explain About Typeglobs?
A29: Type globs are another integral type in perl. A typeglob`s prefix derefrencer is *, which is also the wild card character because you can use typeglobs to create an alias for all types associated with a particular name. All kinds of manipulations are possible with typeglobs.
Q30: What Exactly Is Grooving And Shortening Of The Array?
A30: You can change the number of elements in an array simply by changing the value of the last index of/in the array $#array. In fact, if you simply refer to a nonexistent element in an array perl extends the array as needed, creating new elements. It also includes new elements in its array.
Q31: Define print() function in Perl?
A31: The Perl print() function prints anything it gets as its argument.
Q32: Define say() function in Perl?
A32: The Perl say() function is not supported by older Perl versions. It is like Perl print() function with only one difference that it automatically adds a new line at the end.
Q33: What are scalars?
A33: A scalar contains a single unit of data. They are preceded with a ($) sign. A scalar contains a number, character, reference or a string. A reference is the address of the variable.
Q34: What are hashes?
A34: A Perl hash is a group of unordered key-value pairs. The keys are unique strings and values are scalar values. It is preceded with (%) sign. They can be accessed using their key values.
Q35: Explain use of ‘my’ keyword in Perl?
A35: The ‘my’ keyword restricts a variable to a particular region in which it can be used and accessed. Outside this region, this variable can’t be used.
Q36: What is lexical variable in Perl?
A36: Lexical variables are created using ‘my’ keyword in Perl. They are private variables
Q37: What is warn function in Perl?
A37: The warn function gives the warning on encountering an error but does not exit the script. Script keeps on running.
Q38: Explain returning values from subroutines.
A38: Values can be returned by a subroutine using an explicit return statement. Otherwise it would be the value of the last expression evaluated.
PERL Conclusion Interview FAQs
We know the list of PERL Interview Questions and Answers, PERL Interview Questions and Answers Freshers, PERL Interview Questions and Answers, PERL Interview Questions is overwhelming but the advantages of reading all the questions will maximize your potential and help you crack the interview. The surprising fact is that this PERL interview questions and answers post covers all the basic of the PERL technology and you have to check out the FAQs of different components of PERL too.
However, you will be asked with the questions in the interview related to the above mentioned questions. Preparing and understanding all the concept of PERL technology will help you strengthen the other little information around the topic.
After preparing these interview questions, we recommend you to go for a mock interview before facing the real one. You can take the help of your friend or a PERL expert to find the loop holes in your skills and knowledge. Moreover, this will also allow you in practicing and improving the communication skill which plays a vital role in getting placed and grabbing high salaries.
Remember, in the interview, the company or the business or you can say the examiner often checks your basic knowledge of the subject. If your basics is covered and strengthened, you can have the job of your dream. The industry experts understand that if the foundation of the student is already made up, it is easy for the company to educate the employ towards advance skills. If there are no basics, there is no meaning of having learnt the subject.
Therefore, it’s never too late to edge all the basics of any technology. If you think that you’ve not acquired the enough skills, you can join our upcoming batch of PERL Training in Noida. We are one of the best institute for PERL in noida which provide advance learning in the field of PERL Course. We’ve highly qualified professionals working with us and promise top quality education to the students.
We hope that you enjoyed reading PERL Interview Questions and Answers, PERL Interview Questions and Answers Freshers, PERL Interview Questions and Answers, PERL Interview Questions and all the FAQs associated with the interview. Do not forget to revise all the PERL interview questions and answers before going for the PERL interview. In addition to this, if you’ve any doubt or query associated with PERL, you can contact us anytime. We will be happy to help you out at our earliest convenience. At last, we wish you all the best for your upcoming interview on PERL Technology.
