Re^2: list item comparison

[nitin1704]

in reply to Re: list item comparison
in thread list item comparison

There is no need to check if the $item exists in the hash. When you increment a the value for a key which doesn't exist, the key springs into existence. So lines 8-11 can be replaced by:

$check{$_}++ for @list;

[dasgar]

When you increment a the value for a key which doesn't exist, the key springs into existence.

Didn't know that. Thanks for the info.

However, I'd like to point out one thing. Back when I was first learning Perl, your one line for loop code would have had me thoroughly confused. Based on the original question asked by the OP, I was left with the impression that the OP was a bit of a beginner. In that case, my foreach loop would probably be somewhat easier to follow along and understand.

Plus, I personally find that my foreach loop more closely matches how I would think through the task, which in turn would mean easier code for me to personally maintain. Just a personal preference.

Anyways, thanks for the tip!

[nitin1704]

Yes, it's easier to understand the way you presented it. The one line syntax (statement modifier form) is fairly common in Perl though, and it's great if beginners can pick it up. @OP: This syntax can be used with both loops and conditions. E.g:

if($cond){
    doSomething();
}

can be replaced by:

doSomething() if $cond;

The only catch is that you can execute only one statement per iteration/condition with this syntax. Happy coding!

[johngg]

The only catch is that you can execute only one statement per iteration/condition with this syntax.

That's where do blocks come in handy :-)

knoppix@Microknoppix:~$ perl -E '
> $sayIt = 1;
> do {
>    say q{Hello};
>    say q{World};
>    } if $sayIt;'
Hello
World
knoppix@Microknoppix:~$ 

I hope this is of interest.