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Perl????????????

??

• ???
• ??
• ?????
• ???
  • ??????
  • ??????
  • ??????
    • ?????
    • ?????
  • ?????????
• ????
  • ??????
  • ????
  • ?????
  • ???????
• ???????
  • chomp??
  • chop??
  • substr??
  • split??

???

???? Perl ???????????????????????????3.25e20 ?? 3.25 ?? 10 ? 20 ???

??

??? Perl ????????????????????????? Perl ?????????????????????1_415_926 ? 1,415,926 ????????

?????

? Perl ???????????+????-????*????/?????%?????**?????

10 % 4 # ??? 2
10 ** 3 # ??? 1000

???

???? Perl ???????????????????? Perl ?????????????????????????

??????

??????? Perl ??????????????????????????????????????????

'perl\t\n' # ?? "perl" ???? tab ???????
'perl\\t\\n' # ?? "perl" ???? tab ???????

??????

??????? Perl ????????????????????????????????????????

"perl\tperl1\n" # ?? "perl" ???? tab ???????

??????

? Perl ????????????????.????????x????????+??

?????

??????????????????

"Come" . "on!" # ??? "Comeon!"
"Come" . "." . "on!" # ??? "Come on!"

?????

????????????????????????????????

"Comeon!\t" x 3 # ??? "Comeon! Comeon! Comeon!"
"Comeon!\t" x 3.5 # ??? "Comeon! Comeon! Comeon!"

?????????

Perl ???????????????????????

"12fred34" x 3 # ???? "12fred34" ??????????????
"Z" . 5 * 7 # ??? "Z35"

????

?????????????????? $ ????????????????????????????????????????????

??????

• ??????????$SCALAR ? $scalar ???????
• ????????????????? $score ?????

????

? Perl ?????????? = ? => ???????

$fred = 17;
@scores => [100, 90, 80];

?????

? Perl ???????????+????-????*????/?????%?????**?????

$compute_result = 10 % 4; # ??? 2
$power = 2 ** 3; # ??? 8

???????

?????????????????

my $string6 = "Lady cai";
my $string7 = "I like $string6 !";
print "$string7\n"; # ?? "I like Lady cai !"

???????

chomp??

chomp ???????????????????????????

my $text = "Start from here\n";
print "$text\n"; # ???????
my $text1 = chomp($text); # ????????????? 1
print "$text1\n"; # ???????

chop??

chop ??????????????????

my $scalar1 = "Perl";
my $chop1 = chop($scalar1); # ??????? 'l'
print "$scalar1\n"; # ?? "Per"
print "$chop1\n"; # ?? "l"

substr??

substr ??????????????????

substr(EXPR, OFFSET, LENGTH, REPLACEMENT)

OFFSET ????????????????????LENGTH ????????????????REPLACEMENT ?????????????????

my $string = "I love LadyCai";
my $substr1 = substr($string, 1); # ?? 1 ??????????????? "love LadyCai"
my $substr2 = substr($string, 1, 3); # ?? 1 ???????? 3 ??????? "ove"
my $substr3 = substr($string, 1, 3, "XX"); # ??????? "XX"
print "$substr1\n"; # ?? "love LadyCai"
print "$substr2\n"; # ?? "ove"
print "$substr3\n"; # ?? "XX"

split??

split ??????????????????

split(/PATTERN/, EXPR, LIMIT)

PATTERN ????????????????????LIMIT ??????????????????

print join(':', split(//, 'abc', 1)); # ?? "a:bc"
print join(':', split(//, 'abc', 2)); # ?? "a:b:c"
print join(':', split(//, 'abc', 3)); # ?? "a:b:c"
print join(':', split(//, 'abc', 4)); # ?? "a:b:c"

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