[转 - 改] Perl初级教程 (二)
【对于字符串】
$b = 'BB';
$c = 'CC';
$a = 'AA';
$a = $b . $c; # Concatenate $b and $c = BBCC
$a = $b x $c; # $b repeated $c times
【Perl的赋值语句】
$a = $b; # Assign $b to $a
$a += $b; # Add $b to $a (算数运算)
$a -= $b; # Subtract $b from $a
$a .= $b; # Append $b onto $a (字符运算)
【 互操作性】
$b = 'Pear';
$c = 'CC';
$a = 'Apple';
print $a.' and '.$b;
print "\n"; # 制表符(\t) 换行(\n)
print '$a and $b';
print "\n";
print "$a and $b";
【数组变量】
数组通过以0开始的索引进行访问,方括号内为索引值
@List = ("1",2,'3');
print @List;
> 123
【 数组 赋值/删减】
@List = ("1",2,'3',"Array");
@array = (5..15); #序列化列表5~15;print @List;
print "\n";
print @array;
>123Array
56789101112131415
# push Statement.
push(@List,"Added");
print @List;
print "\n";
push(@List,@array);
print @List;
>123Array
123Array56789101112131415
# pop Statement.
@List = ("1",2,'3',"Array");
@array = (5..15);
push(@List,@array);
$e = pop(@List);
$f = pop(@List);
print $f;
print "\n";
print @List;
print "\n";
$f = @List;
print $f;
> 14
123Array568910111213
13
# 数组也可以用来为多个标量进行赋值
@List = ("1",2,'3',"Array");
@array = (5..15);
push(@List,@array);
$e = pop(@List);
$f = pop(@List);
print "\n";
print $e;
print "\n";
print $f;
print "\n";
($e,$f,$a) = @List; # 按照数组顺序项给变量赋值。
print "\n";
print $e;
print "\n";
print $f;
print "\n";
print $a;
> 15
14
1
2
3
# 最后,你可能想知道列表中最后一个元素的索引值,可以用这个表达式:
print $#List;
> 12;
($a, $b) = ($c, $d); # Same as $a=$c; $b=$d;
($a, $b) = @food; # $a and $b are the first two items of @food.
($a, @somefood) = @food; # $a is the first item of @food , @somefood is a list of the others.
(@somefood, $a) = @food; # @somefood is @food and $a is undefined.
- Make people around you successful is the biggest contribution to ourselves. -