 2 Perl 

 Perl    Learning by Acting 



  Easy     easy.pl

print "Hello, user..\n";

print "Perl is easy for you\n";

  perl  unix  #!/usr/bin/perl   easy.pl 

E:\> perl easy.pl

Hello, user..

Perl is easy for you

 Easy.pl   print  print    "\n"     "\n"

print "Hello, user..";

print "Perl is easy for you\n";



print "\n\nHello, user..\n";

print "Perl is easy for you\n\n";

    Perl   ( ; )     ;    Error 

 ( Comment )

 Perl  ( # )    

print "Hello, user..\n"; # print "hello"

#print "Perl is easy for you\n";

    /**/       Perl   #  



 Perl   Perl  2   

 ( Scalar )
 ( Array )

 Scalar

 Scalar    ( Integer )  ( String )  Scalar       Scalar  ( $ )  

$name = "kwangd";

$age1 = 36;

$age2 = age1;

$a = $b = $c = 3;

$address = "Nokornpathom 73210";

  Scalar  $name , $age  $address  Perl  Integer  String    Perl    

 "."  '..'   

$name = "kwangd"



$name = 'kwangd';

   

$name = "kwangd";

$name = 36;

 $name   36

 Array

 ..  Perl  @  

@array = ( "black" , "white" , "yellow" , "green" );

  array  4   String  black , white , yellow  green   Scalar    $   0 , 1 , 2  3   (  )

   print  Array1.pl 

 ARRAY1.PL

@array = ( "black" , "white" , "yellow" , "green" );
print "@array\n";



C:\> perl array.pl

black white yellow green

   Array1.pl  Array2.pl

 ARRAY2.PL

@array = ( "black" , "white" , "yellow" , "green" );
print "@array\n";
print "$array[0]\n";
print "$array[1]\n";
print "$array[2]\n";
print "$array[3]\n";



C:\> perl array2.pl

black white yellow green

black

white

yellow

green

  Scalar     

@array = ( "black" , 20 , 'yellow' , 100 );

Perl    Array3.pl  Array2.pl 

 Array3.pl

@array = ( "black" , 20 , 'yellow' , 100 );
print "@array\n";
print "$array[0]\n";
print "$array[1]\n";
print "$array[2]\n";
print "$array[3]\n";



C:\> perl array3.pl
black 20 yellow 100
black
20
yellow
100

 Associative Array

Associative Array    ""   0  1 ,  2  3   % 

%age = ( "kwangd" , 27 , "kai" , 30 , "Bee" , 34 );

   1 

%age = ( "kwangd" , 27 , "kai" , 30 , "bee" , 34 );

print " $age{'kwangd'}\n";

print " $age{'kai'}\n";

print " $age{'bee'}\n";



27
30
34

  $   Associative Array  CGI



   .. 1.  Scalar  $  @ 2.  $  @  3.     . (   )

$name = "kwangd";

$_data = 231;

$m_address = "bkk";

$och! = "True";

$data_from_field_email = "[email protected]";

  $_data  $och!   $_data  $   $och!  (!) 

   Perl    $name  $Name    

 ( Standard Input )

 Perl  scanf()  readln()   <STDIN>  Standard Input   stdin1.pl  

 stdin1.pl

<STDIN>



C:\> perl stdin1.pl
hello
C:\>

    <STDIN>   

$a = <STDIN>;

 $a   print

print "value is $a\n";

 stdin1   

 stdin2.pl

print "what is your name ? , ";
$name = <STDIN>;
print "\nhello $name";

 $name = <STDIN>  readln(name)  scanf("%s",&name)    

Perl 

 Perl   4    ( + ) ,  ( - ) ,  ( * )  ( / ) 

 think1.pl

$a = 5;
$b = 10;
$num1 = $a + $b;
$num2 = 5 * 4;
$answer = $num1 + $num2;
print "$answer";



C:\> perl think1.pl
20



 $a  5  $b  10
 $num1  $a  $b (  15 )
 $num2  5  4 (  20 )
 $answer  $num1  $num2 ( 35 )
 $answer 

   ( - )  

$a = -5;

$b = 10;

 $a  $b 

$num1 = $a + $b;

 $num1  5   ( -5 ) + 10  5



 Perl    Perl  4     ,     think2.pl 

 think2.pl

$a = 4;
$b = 4;
$c = 6;
$d = 2;
$answer = ( $a + $b * $c ) / $d ;
print "$answer";



C:\> perl think2.pl
14

  $a, $b, $c  $d   $b  $c  $a  $d

   $num1  $num2 

 think3.pl

print "\nEnter num1 : ";
$num1 = <STDIN>;
print "\nEnter num2 : ";
$num2 = <STDIN>;
$answer = $num1 + $num2;
print "\nanswer is $answer";



C:\> perl think3.pl
Enter num1 : 12
Enter num2 : 3
answer is 15

  think3.pl  3   ,    think3.pl  ,  