web后端 - 关于php中嵌入html代码时结束符“？>”位置为什么这样放置？

大家好，本人初学php，关于html和php代码嵌入有点不明白，

举个例子：

<code><?php if ( $missingFields ) { ?>
<p class="”error”">There were some problems with the form you submitted.
Please complete the fields highlighted below and click Send Details to resend the form.</p>
<?php } else { ?>
<p>Thanks for choosing to join The Widget Club. To register, please fill
in your details below and click Send Details. Fields marked with an asterisk(*) are required.</p>
<?php } ?>
</code>

为什么这里遇到“}”就把它单独放置在<?php ?>中。为什么不能写成这样？

<code><?php if ( $missingFields ) { 
<p class=”error”>There were some problems with the form you submitted.
Please complete the fields highlighted below and click Send Details to resend the form.
 } else { 
<p>Thanks for choosing to join The Widget Club. To register, please fill
in your details below and click Send Details. Fields marked with an asterisk(*) are required.</p>
 } </code>

非常感谢，解疑答惑！

回复内容：

大家好，本人初学php，关于html和php代码嵌入有点不明白，

举个例子：

<code><?php if ( $missingFields ) { ?>
<p class="”error”">There were some problems with the form you submitted.
Please complete the fields highlighted below and click Send Details to resend the form.</p>
<?php } else { ?>
<p>Thanks for choosing to join The Widget Club. To register, please fill
in your details below and click Send Details. Fields marked with an asterisk(*) are required.</p>
<?php } ?>
</code>

为什么这里遇到“}”就把它单独放置在<?php ?>中。为什么不能写成这样？

<code><?php if ( $missingFields ) { 
<p class=”error”>There were some problems with the form you submitted.
Please complete the fields highlighted below and click Send Details to resend the form.
 } else { 
<p>Thanks for choosing to join The Widget Club. To register, please fill
in your details below and click Send Details. Fields marked with an asterisk(*) are required.</p>
 } </code>

非常感谢，解疑答惑！

因为

标签属于html而不是php语言，所以不能加到php起止符号内

表示他为php的 代码块结束符号“}”

因为

<code><p class="”error”">There were some problems with the form you submitted.
Please complete the fields highlighted below and click Send Details to resend the form.</p>
</code>

不是合法的PHP代码．

1. 在<?php ?>中的是php代码，第二种写法，很明显标签<p></p>中的内容不是php代码。

2. 如果想要用第二种写法，可以这样写：

<code><?php if ( $missingFields ) { 
echo '<p> ... ';
 } else { 
echo '<p> ... </p>';
 } 
?></code>

所有的非html代码都要嵌入在<?php ?>内，而所有在<?php ?>里面的都会被解析为php代码，按照你的想法，那一对<p></p>标签里的内容不属于php代码，所以应该是这样分段嵌入的：

<code><?php if ( $missingFields ) { ?>
xxx
<?php } else { ?>
xxx
<?php } ?></code>

7048
其实应该这样理解
在php里， ?> 表示开始输出html，

可以这样：

<code><?php if ( $missingFields ): ?>
    <p class="error">There were some problems with the ....</p>
<?php else: ?>
    <p>Thanks for choosing to join The Widget Club....</p>
<?php endif; ?></code>

语言PHP的语法起始标签就是 <?php ?> PHP的语言决定必须这么写!!!