Coding Tag offers you the PERL interview questions with a detailed explanation of every section covering PERL language basics that are required before facing a PERL developer interview.





1) PERL stands for?

Practical Extraction and Report Language

2) Who Developed the PERL language?

Larry Wall



3) What is PERL?

Perl is the most prominent interpreted open source programming language containing a wide range of libraries, programmers, and resources used for various tasks related to web development, system administration, network programming, GUI development, report language, practical extraction, and other bulk text processing tasks.

PERL is trendier nowadays due to its rapid development cycle and text manipulation capabilities.



4) List some features of PERL?

PERL contain effective inbuilt regular expressions for Data Transformation and Filtration

Support web data encryption including e-commerce transactions

Support DBI package for easy web-database integration

Support Unicode, procedural and object-oriented language

SWIG and XS can be used for Perl interfaces with external C++/C libraries

Perl is the request-response type of language

A single script can be used in multiple devices

Platform independent

It is simple to learn the Perl language

5) What is the main reason for choosing PERL language as a scripting language?

Following are the reasons for selecting PERL languages as a scripting language:

Perl single line of code is equivalent to multiple line codes in another language.

A single script can be used in multiple devices

You don't need to implement our own logic as in Python or C

It contains a huge built-in parsing interpreter, pattern matching, and regular expression.

6) Differentiate Between USE and REQUIRE?

USE

REQUIRE

Act at compile time (Perl compilation phase)

Act at runtime

A file extension is not required

A file extension is not required

Used for only modules

Used for modules and libraries



7) How can you empty an array?

There are three methods to empty an array that is as follow:

By setting length placing its length to any negative number.

By assigning a null list().

Set an array to undef to clear it.



8) Is the length of Perl code is same as in C++ and Java code?

Perl code is less as a comparison to Java and C++ language since Perl code is the one-fifth size of the C++ code, we need less to maintain, write, and debug.



9) Is Binary extension can be load dynamically?

Yes, the Binary extension can be loaded dynamically if your systems support it.



10) Between the list and the terms, which have the highest precedence?

Terms have the highest precedence in comparison with list operators. Terms are variables, expressions in parenthesis, quotes, etc.



11) Name the command that is used to display the series of warning messages of the code?

The -w Command-line option can be used.

12) What do you mean by the @ARGV array?

The @ARGV array is known as the special array to store the command line argument, working is identical to the normal array i.e. first and the second argument will be $ARGV[0] and $ARGV[1] respectively.



13) Explain Database Connectivity in PERL?

First, you have to use the DBI module

my $dbh = DBI->connect('dbi:Oracle:orcl', 'username', 'password',)

where you can use your password and username



14) CPAN

CPAN stands for Comprehensive Perl Archive Network act as a directory containing a huge number of open-source, ready to use Perl modules, documentation, source and ports containing a list of the operating system.



15) Name the options that can be used to wrap scripts inside loops?

-n or -p options can be used.



16) Between Aliases and references, which is considered as faster?

Aliases are considered faster.



17) Mention the difference between die and exit in Perl?

die outputs an error message whereas exit does not

die always accepts string or nothing but never accepts a number as an argument.



18) How many types of variables found in PERL?

There are three types of built-in variables found in PERL i.e. Array, Scalar, and Hash.



19) Which variable symbol is $ in PERL?

Scalar



20) Is PERL case sensitive language?

Yes

21) Which operator is used to call a method in PERL?

->(Arrow Operator)



22) Name the loop control keywords in PERL?

Last

Redo

Next

23) Tell Function

Tell function is used to return the present spot of reading pointer in bytes or used to find your position within the file.



Syntax:



tell FILEHANDLE tell



24) Name the functions used to implement the Stack in PERL?

shift() and push()



25) How can we concatenate string in Perl language?

These can be done with the dot operator.



26) What do you mean by ivalue in PERL?

Ivalue is considered as a scalar value, used to store the expression's result. It represents a data space in memory and occurs on the left side of the expression.



27) Name the function which eliminates the last character from the expression?

Chop function and chomp function removes the character if there is a match.



28) How can you delete an existing file in Perl?

unlink("/usr/text/file8.txt");



Where file8 is the existing file



29) How can you rename any file in Perl language?

Rename("/usr/text/file7.txt", "/usr/text/file7.txt");



30) Which keyword is used if we want to re-executes the block code without re-valuating any condition of the loop?

Redo keyword can be used