use strict;
#這里是兩個(gè)數(shù)組
my @i =('1','2','3');
my @j =('a','b','c');

#在進(jìn)行處理之前，我們把他們先打印出來(lái)，看一看他們的樣子
print "In main program before calling subroutine:i="."@i\n";
print "In main program before calling subroutine:j="."@j\n";

#然后我們通過(guò)子程序進(jìn)行處理
reference_sub(@i,@j);
print "In main program after calling subroutine:i="."@i\n";
print "In main program after calling subroutine:j="."@j\n";
#下面是子程序
sub reference_sub
{
 my (@i,@j)=@_;
 print "In subroutine:i="."@i\n";
 print "in subroutine:j="."@j\n";

 #這里我們對(duì)@_的處理用pop,和shift來(lái)進(jìn)行
 push(@i,'4');
 shift(@j);
}

F:\&;perl\a.pl
In main program before calling subroutine:i=1 2 3
In main program before calling subroutine:j=a b c
In subroutine:i=1 2 3 a b c
in subroutine:j=
In main program after calling subroutine:i=1 2 3
In main program after calling subroutine:j=a b c
F:\&;

use strict;

#這里是兩個(gè)數(shù)組
my @i =('1','2','3');
my @j =('a','b','c');

#在進(jìn)行處理之前，我們把他們先打印出來(lái)，看一看他們的樣子
print "In main program before calling subroutine:i="."@i\n";
print "In main program before calling subroutine:j="."@j\n";

#然后我們通過(guò)子程序進(jìn)行處理
reference_sub(\@i,\@j);#在這里我們添加了反斜線，也就是pass byreference（傳入引用，在大駱駝書(shū)中第六章翻譯）
print "In main program after calling subroutine:i="."@i\n";
print "In main program after calling subroutine:j="."@j\n";
#下面是子程序
sub reference_sub
{
 my ($i,$j)=@_;#引用也是一種特殊的數(shù)據(jù)形式，它們?cè)贎_中都被當(dāng)成標(biāo)量變量來(lái)儲(chǔ)存
 print "In subroutine:i="."@$i\n";所以這里引用它們的時(shí)候，我們?cè)谒麄兦懊嫣砑恿藘蓚€(gè)符號(hào)，@代表這是一個(gè)數(shù)組，$代表著是一個(gè)二次引用。
 print "in subroutine:j="."@$j\n";
    print "In subroutine:the third element is $$j[2]\n";#當(dāng)引用數(shù)組中的一個(gè)元素的時(shí)候第一個(gè)$和后面的j[2]代表數(shù)組中的第三個(gè)元素，而第二個(gè)$代表的就是二次引用
 #這里我們對(duì)@_的處理用pop,和shift來(lái)進(jìn)行
 push(@$i,'4');
 shift(@$j);
}

F:\&;perl\a.pl
In main program before calling subroutine:i=1 2 3
In main program before calling subroutine:j=a b c
In subroutine:i=1 2 3
in subroutine:j=a b c
In subroutine:the third element is c
In main program after calling subroutine:i=1 2 3 4
In main program after calling subroutine:j=b c
F:\&;