1.Multi-Line Strings
In Perl, we can handle a multi-line string  by using a ENDOFDOCUMENT.

Example:
---------

#!c:\www\Perl\bin
$sentence = <<"ENDOFDOCUMENT";
Best regards,
Have a nice day!
Take care, and 
All the best of luck ..
ENDOFDOCUMENT


warn "The sentence is:\n '$sentence'";

outputs:
C:\www\PERL>test.pl
The sentence is:
 'Best regards,
Have a nice day!
Take care, and
All the best of luck ..
' at C:\www\PERL\test.pl line 10.


2 Numeric Functions
abs:
---
To get the absolute value of a number, we use:
abs($number); # var1 is 3.4

int:
---
To convert a floating point number to an integer, we use 
int($float_number);

round:
-----
To round a float, use the "C" style: to the nearest intege
$number = 23.56
sprintf("%.xf", $number;
"x" can take the value 0 ( nearest integer), 1 ,2 ...

sprintf:
--------

To convert a number into string format, use:
sprintf ( FORMAT_STRING, LIST_OF_VALUES );

Example:
my $number = 2.17456;
my $number  = sprintf("%05.3f",$number);

Will be converted into a string of 5 characters 
and 3 decimals; that is: 2.175

To convert a string into a number, we add 0:
Example
My $number1 = '34.786';
my $number2 = $number1+0; 


random:
-------
Use rand

Example:
$any_number = rand;
print 100000000.00 * $any_number ;

conversion:
----------
Convert a number to a string:
my $number = 3.1416
my $word= $number .= ''; 
will becomes a string: '3.14116'