Perl Simple Functions

I try to start programming with perl, with small simple scripts, but I got stuck a little. I type the principle of the array, trying now to attack functions. I am writing a function that gives me the result of the addition and the product of 2 numbers. So at first I wrote this:

Code:

---

print "Enter a number :";
$num1 = <>;
print "Enter another number :";
$num2 = <>;
@pool = ("$num1","$num2" );

---

From the need, I used my "@pool" for addition and multiplication. So I tried something like that with the addition in helping me to start a site on perl:

Code:

---

sub add
{ 
    $sum = 0;
    foreach $item (@_)
    {
      $sum += $item;                     
    }
    return $sum;
}
$result = add(@pool);
print "Sum of @pool is $result";

---

I have the result (on 2 lines, moreover, why?) But now I want the function that also gives me the result of the product, but I can not, I do not use the right operator or I do not know something?

Someone can help quickly? How can I implement multiplication operation in Perl?

When you do that:

Code:

---

print "Enter a number :";
$num1 = <>;

---

$num1 will contain what you typed, ie a string terminated by a newline. So @pool contains two string terminated by \n and when you do:

Code:

---

print "Sum of @pool is $result";

---

when @pool is valued, its content is printed, the two strings with \n, or line breaks obtained. Why add your works anyway? because when you do it:

Code:

---

$sum += $item ;

---

the + strength assessment of $item (which is a string terminated by \n) in a digital environment, and therefore it is evaluating as $item number is added to $sum.

If you do:

Code:

---

print "Enter a number :";
$num1 = 0 + <>;

---

It will force the evaluation of digital input and store it as a numeric value in $num1 (and you'll see the difference in print from @pool: you'll just number without newline)

Another point:
It would be better to write:
@pool = ($num1, $num2);
pool will contain a copy of the values of $num1 and $num2 evaluated when the assignment.

Finally, I do not know if what you're trying to look like this, but it should give you some ideas:

Code:

---

    sub add_mul
    {   
      $sum = 0;
      $mul = 1;
      foreach $item (@_)
      {
        $sum += $item;
        $mul *= $item;
      }
      return ($sum, $mul);
    }
   
    @result = add_mul(@pool);
    print "Sum of @pool is $result[0] and Mul is $result[1]";

---

After the procedure can be written in a slightly more condensed, but it's just a matter of style:

Code:

---

    sub add_mul {
      my ($sum, $mul) = (0, 1);
      foreach (@_) {
          ($sum, $mul) = ($sum + $_, $mul * $_);
      }
      return ($sum, $mul);
    }

---

Thank you! Meanwhile, I managed to do that

Code:

---

print "Enter a number :";
$num1 = <>;
print "Enter another number :";
$num2 = <>;
@pool = ("$num1","$num2" );
sub addprod
{
  $addresult = $_[0] + $_[1];
  print "The sum is : $addresult\n";
  $prodresult = $_[0] * $_[1];
  print "The product is: $prodresult\n";
}
addprod (@pool)

---

For info: in perl, no need to declare before the subs. Personally (and I think most people did the same) I put them all one after another at the end. And in principle we declare variables with my (or our if necessary), as that eg
my $addresult = $_[0] + $_[1];

But in your case, no need to create a variable, just do it, with brackets to remain in the digital environment:
print "The sum is : ".($_[0]+$_[1])."\n";

I think it is necessary for your learning to use:
use strict;
at the beginning of your code. It will go wrong when something is not good "clean".

Quote:

---

I think it is necessary for your learning to use:
use strict;
at the beginning of your code. It will go wrong when something is not good "clean".

---

It is especially wrong if we use variables without having declared with my (which declares a variable as local to the block or it is) or as overall (our, jobs scarce, creating an overall package), or as local variable block, which override the block in a variable of the same name already declared (local, mostly reserved for local override of $ _, $, etc)

A basic template for the code can be read

Code:

---

#!/usr/bin/perl
use strict;
use warnings;
 .............................
__END__

---

This is after __END__ that is not interpreted, you can put the code not valid, while editing, notes, personal ... and documentation in pod format