January 2021
Intermediate to advanced
505 pages
9h 45m
Chinese
Content preview from PHP编程：第4版
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82
｜
第
4
章
字符串
起来的字符串中
PHP
认可的转义序列。
表4-1：双引号括起来的字符串中的转义序列
转义序列 字符表示
\"
双引号
\n
换行符
\r
回车符
\t
制表符
\\
反斜杠
\$
美元符号
\{
左大括号
\}
右大括号
\[
左中括号
\]
右中括号
\0
到
\777
用八进制数表示的
ASCII
字符
\x0
到
\xFF
用十六进制数表示的
ASCII
字符
\u UTF-8
编码
如果在双引号括起来的字符串中发现未知的转义序列（例如，一个反斜杠后跟一个不在
表
4-1
中的字符），它将被忽略（如果你的警告级别设置的是
E_NOTICE
，
PHP
在执行的
时候会产生一个这样的未知转义序列警告）：
$str = "What is \c this?"; //
未知转义序列
echo $str;echo $str;
What is \c this?
here
文档
使用
heredoc
可以很容易地把多行字符串放在程序中，如下所示 ：
$clerihew = <<< EndOfQuote
Sir Humphrey Davy
Abominated gravy.
He lived in the odium
Of having discovered sodium.
EndOfQuote;
echo $clerihew;
Sir Humphrey Davy
Abominated gravy.
He lived in the odium
Of having discovered sodium.
引用字符串常量
｜
83
<<<
符号告诉
PHP
解析器你正在书写一个
heredoc
。你可以选择标识符 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
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.