求婚示爱的Perl代码之注释篇

    $_ = $q;
    $q =~ tr/[]a-z/[]l-p r-za-k/;
    my(@ever) = 1 .. &l;
    my $mine = $q;
    sub p {
        print @_;
    }
    be $mine foreach (@ever);

代码注释

 #打开警告开关
    BEGIN { $^W = 1; }

    #符号引用检查
    use strict 'refs';

    #数组中第一个元素的索引号
    my $f  = $[;
    my $ch = 0;

    #注意字符串中有个换行符
    my $q = r("ntfgpfdfal,thg?bngbjnaxfcixz");
    $_ = $q;
    $q =~ tr/[]a-z/[]l-p r-za-k/;

    my (@ever) = 1 .. &l;
    my $mine = $q;

    be($mine) foreach (@ever);

    #获取字符串的长度
    sub l {
        length $_;
    }

    #反转字符串
    #join, 0均为凑数用，可以省略
    sub r {
        join '', reverse( split( //, $_[0], 0 ) );
    }

    #提取字符串中的子串
    sub ss {
        substr $_[0], $_[1], $_[2];
    }

    #输出
    sub p {
        print @_;
    }

    #从字符串的前半段和后半段交替提取一个字符并输出
    sub be {
        $_ = $_[0];
        p( ss( $_, $f, 1 ) );
        $f += l() / 2;
        $f %= l();
        ++$f if $ch % 2;
        $ch++;
    }

代码重写

 #!/usr/bin/env perl

    use strict;
    use warnings;
    use utf8;

    my $pointer   = 0;
    my $character = 0;
    my $string    = reverse("ntfgpfdfal,thg?bngbjnaxfcixz");
    $string =~ tr/a-z/l-p r-za-k/;
    foreach ( 1 .. length($string) ) {
        print substr( $string, $pointer, 1 );
        $pointer += length($string) / 2;
        $pointer %= length($string);
        ++$pointer if $character % 2;
        $character++;