Perl语言入门-第五章-输入与输出-习题

最新推荐文章于 2024-10-16 15:00:08 发布

转载最新推荐文章于 2024-10-16 15:00:08 发布 · 152 阅读

本文提供了三个Perl编程练习示例，包括字符串反转程序、格式化输出字符串的程序及一个涉及用户输入宽度来定制输出格式的程序。这些示例有助于理解Perl中的基本语法和控制结构。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1. 习题

2. 代码与输出

cat_reverse.pl

1 # -----------------------------------------------------------#
2 # Source: Learning Perl, chapter5, exercise-1
3 # Date: 2012-01-15
4 # Author: xiaodongrush
5 #-----------------------------------------------------------#
6 use 5.010;
7 while(<>) { chomp; unshift @array, $_; }
8 foreach( @array) { say $_; }
9 <STDIN>
10 # @_表示子程序的参数列表，$_是Perl的老地方，容易混淆

printf_example.pl

1 # -----------------------------------------------------------#
2 # Source: Learning Perl, chapter5, exercise-2
3 # Date: 2012-01-15
4 # Author: xiaodongrush
5 #-----------------------------------------------------------#
6 use 5.010;
7 say " Input several str! (Use Control+Z to Stop Input). ";
8 while(<>) { chomp; push @strs, $_; }
9 say " 1234567890 " x 4;
10 foreach( @strs) { printf " %20s\n ", $_; }
11 <STDIN>

printf_example_2.pl

1 # -----------------------------------------------------------#
2 # Source: Learning Perl, chapter5, exercise-3
3 # Date: 2012-01-15
4 # Author: xiaodongrush
5 #-----------------------------------------------------------#
6 use 5.010;
7 say " Input several str! (Use Control+Z to Stop Input). ";
8 while(<>) { chomp; push @strs, $_; }
9 print " The Width of the Rule Line Width = "; $width = <STDIN>;
10 print " 1234567890 " x ( $width/ 10);
11 foreach( 1.. 9) { if( $_ <= ( $width% 10)) { print $_; } } say;
12 foreach( @strs) { printf " %20s\n ", $_; }
13 <STDIN>