CODEWITHSUNDEEP
perl
Nikhil Hegde
Nikhil Hegde

Reputation: 341

What is the function of this code expression?

I'm confused with the function of the regular expression:

/\[\]$/

I tried out a short perl code to understand it but I'm still confused. The code output is Else

my $addr2 = {[{'firstname' => 'Nikhil', 'lastname' => 'Hegde'}, {'firstname' => 'Nikhil2', 'lastname' => 'Hegde2'}]};
if($addr2 =~ /\[\]$/) {
    print "If\n";
} 
else {
    print "Else\n";
}

I thought that /\[\]$/ would point to whether the value is an array or not but that doesn't seem to be the case. I then thought that maybe the value has to end with an array considering that there is a $ in the regular expression. So, I tried substituting:

my $addr2 = {[{'firstname' => 'Nikhil', 'lastname' => 'Hegde'}, {'firstname' => 'Nikhil2', 'lastname' => 'Hegde2'}],[]};

but that doesn't work either. The code output remains Else.

Can anyone help me in understanding the expression /\[\]$/? What regular matching does it do? Thanks!

Upvotes: 0

Views: 69

Answers (1)

yoniyes
yoniyes

Reputation: 1020

A regular expression checks matching of strings. In your case, you tried matching a hash reference. That's why your code went to the else block.

Now, the /\[\]$/. It matches any string that has a literal [] at the end of it. For example, the string my $str = "just an example []" would match this regex.

Upvotes: 7

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