August 2018
Beginner to intermediate
382 pages
7h 14m
Chinese
Content preview from Perl语言入门
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34
｜
第
2
章
和数字一样，字符串也可以写作直接量。这其实就是在
Perl
程序中书写字符串的方
式：单引号圈引的字符串以及双引号圈引的字符串。
单引号内的字符串直接量
单引号内的字符串直接量就是写在一对单引号（
'
）内的一串字符。前后两个单引号
只是边界，并不是字符串的内容，用于让
Perl
判断字符串的开头与结尾：
'fred' #
总共
4
个字符：
f
、
r
、
e
和
d
'barney' #
总共
6
个字符
'' #
空字符串（没有字符）
34
｜
第
2
章
和数字一样，字符串也可以写作直接量。这其实就是在
Perl
程序中书写字符串的方
式：单引号圈引的字符串以及双引号圈引的字符串。
单引号内的字符串直接量
单引号内的字符串直接量就是写在一对单引号（
'
）内的一串字符。前后两个单引号
只是边界，并不是字符串的内容，用于让
Perl
判断字符串的开头与结尾：
'fred' #
总共
4
个字符：
f
、
r
、
e
和
d
'barney' #
总共
6
个字符
'' #
空字符串（没有字符）
'
⅚
∞
☃☠
' #
某些“宽”
Unicode
字符
除了单引号和反斜线字符外，单引号内所有字符都代表它们自己。如果要在字符串中
使用单引号和反斜线，需要添加一个反斜线用作转义：
'Don\'t let an apostrophe end this string prematurely!'
'the last character is a backslash: \\'
'\'\\' #
两个字符，一个是单引号，一个是反斜线 ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.