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if ($str eq '') {<br />
&nbsp; return NULL;<br />
}
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<div>
There seem to be different interpretations of the question, so maybe some clarification is in order.<br />
null or NULL are not keywords in Perl, so do you mean an empty string? &nbsp;by &quot;not initialized&quot; do you mean undef?
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<div>
&gt;but does perl support null<br />
what characteristics do you want this null to have?<br />

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It is very similar to the object created in java.<br />
class obj; // state 1<br />
obj = new class(); // state 2<br />
<br />
I &nbsp;need to check in the if condition whether the $input is in obj's state 1
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<div class="content wysiwyg-content">
sub func1()<br />
<b>my $input = shift;<br />
if (check $input is null... not initialized)<br />
&nbsp; &nbsp;return NULL;</b><br />
else <br />
&nbsp;execute something else<br />
<br />
I need help in writing the part enclosed in bold.
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sub func1()
my $input = shift;
if (check $input is null... not initialized)
   return NULL;
else 
 execute something else

I need help in writing the part enclosed in bold.

if condition in perl

Perl is a high-level, general-purpose, interpreted, dynamic programming languages with over 25 years of development. Perl 5 runs on over 100 platforms from portables to mainframes and is suitable for both rapid prototyping and large-scale development projects.  Perl gained widespread popularity as a Common Gateway Interface (CGI) scripting language, in part due to its regular expression and string parsing abilities. In addition to CGI, Perl is used for graphics programming, system administration, network programming, finance, bioinformatics, and other applications.

Perl

Kernel programming for Linux operating systems can be done with many different languages; C, C++, Python, Perl and Java, which are some of the most common languages used.There are also many different varieties of Linux, such as Ubuntu, Fedora and OpenSUSE.