Perl - variable－逗點大的雨滴

#!/usr/bin/perl
#string
$str = "hello ";

#integer
$val1 = 1;
$val2 = 2;
$three = 3;

#calculate
$sum_val = $val1 + $val2;
$sum_str = $val1 . $val2;#note: .
$min_val = $val2 - $val1;

#float
$float1 = 0.1;
$float2 = 0.2;
$sum_fl = $float1 + $float2;

#printf
printf "printf scalar\n===============\n";
printf "$str\n";
printf "printf string : $sum_str\n";
printf "$sum_val = $val1 + $val2 \n";
printf "$min_val = $val2 - $val1\n";
printf "$sum_fl = $float1 + $float2\n";
print "x feature", $str x $three."\n";#note: must be print

#print
print "Multiplication ",$sum_val," * 3 = ",$sum_val * 3,"\n\n";#note:print

#array
printf "printf array\n===============\n";
@int_ary = (1,2,3,4,5); #note:()
@str_ary = ("one","two","three","four","five");

printf "printf one element ".$int_ary[0]." ".$str_ary[0] ."\n";

printf "element number of ary = ".$#int_ary."\n";#note: start at 0
   #multi_array
   @multi_int_ary = ([1,2],[3,4]);
   printf "multi int array ".$multi_int_ary[0][1]."\n";

   @multi_str_ary=(["one","two"],["three","four"]);
   printf "multi string array ".$multi_str_ary[0][1]."\n";

   #other array
   $week{"day"} = ["sunday","monday","tuesday","wednesday","thursdsy","friday","saturday"];#note must be [ and ]
   printf "other array day ".$week{"day"}[0]."\n";

   #complexities array
   @a = ("a","red",20);
   @b = ("b","black",13);
   @c = ("c","white",25);
   @people = (\@a,\@b,\@c);
   printf "complexities array ".$people[1][2]."\n";

   @int= (1,2,3,4,5);
   @string = ("one","two","three" ,"four","five");
   @float = (1.0,2.0,3.0,4.0,5.0);
   @variable = (\@int,\@string,\@float);
   printf "complexties array ".$variable[1][3]."\n";

result

printf scalar
===============
hello
printf string : 12
3 = 1 + 2
1 = 2 - 1
0.3 = 0.1 + 0.2
x featurehello hello hello
Multiplication 3 * 3 = 9

printf array
===============
printf one element 1 one
element number of ary = 4
multi int array 2
multi string array two
other array day sunday
complexities array 13
complexties array four