How to turn on Perl warnings? Why is that important

Q

How to turn on Perl warnings? Why is that important?

✍: Guest

A

Perl is very forgiving of strange and sometimes wrong code, which can mean hours spent searching for bugs and weird results. Turning on warnings helps uncover common mistakes and strange places and save a lot of debugging time in the long run. There are various ways of turning on Perl warnings:

For Perl one-liner, use -w option on the command line.
On Unix or Windows, use the -w option in the shebang line (The first # line in the script). Note: Windows Perl interpreter may not require it.

2007-11-19, 5922👍, 0💬

What is encapsulation technique
What is encapsulation technique? Hiding data within the class and making it available only through the methods. This technique is used to protect your class against accidental changes to fields, which might leave the class in an inconsistent state. 2007-11-16, 6445👍, 0💬

Some nested data structure
Assume that $ref refers to a scalar, an array, a hash or to some nested data structure. Explain the following statements: $$ref; # returns the scalar pointed by $ref. $$ref[0]; # returns the first element of the array pointed by $ref. $ref->[0]; # returns the first element of the array pointe... 2007-11-21, 6334👍, 0💬

Why do you use Perl
Why do you use Perl? Perl is a powerful free interpreter. Perl is portable, flexible and easy to learn. 2007-11-19, 6170👍, 0💬

What is Perl one-liner
What is Perl one-liner? There are two ways a Perl script can be run: From a command line, called one-liner - That means you type and execute immediately on the command line. You'll need the -e option to start like "C:\ %gt perl -e "print \"Hello\";". One-liner doesn't mean one Perl statement. One-li... 2007-11-19, 6110👍, 0💬

What is the difference between a NULL pointer and a void pointer
What is the difference between a NULL pointer and a void pointer? A NULL pointer is a pointer of any type whose value is zero. A void pointer is a pointer to an object of an unknown type, and is guaranteed to have enough bits to hold a pointer to any object. A void pointer is not guaranteed to have ... 2007-11-13, 6058👍, 0💬

How to turn on Perl warnings? Why is that important
How to turn on Perl warnings? Why is that important? Perl is very forgiving of strange and sometimes wrong code, which can mean hours spent searching for bugs and weird results. Turning on warnings helps uncover common mistakes and strange places and save a lot of debugging time in the long run. The... 2007-11-19, 5923👍, 0💬

Does Perl have reference type?
Does Perl have reference type Yes. Perl can make a scalar or hash type reference by using backslash operator. For example: $str = "here we go"; # a scalar variable $strref = \$str; # a reference to a scalar @array = (1..10); # an array $arrayref = \@array; # a reference to an array Note that the ref... 2007-11-20, 5842👍, 0💬

How to dereference a reference
How to dereference a reference? There are a number of ways to dereference a reference: Using two dollar signs to dereference a scalar like: $original = $$strref; Using @ sign to dereference an array like: @list = @$arrayref; Similar for hashes. 2007-11-21, 5834👍, 0💬

Perl uses single or double quotes to surround a zero
Perl uses single or double quotes to surround a zero or more characters. Are the single(' ') or double quotes (" ") identical? They are not identical. There are several differences between using single quotes and double quotes for strings: The double-quoted string will perform variable interpolation... 2007-11-26, 5700👍, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.