blocks|key|1450731|text|你可以这样做if+else语句：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1450732|<?php
if+($something)+{
+++echo+'one+conditional+line+of+code';
+++echo+'another+conditional+line+of+code';
}


if+($something)+echo+'one+conditional+line+of+code';

if+($something)
echo+'one+conditional+line+of+code';
echo+'a+NON-conditional+line+of+code';+//+this+line+gets+executed+regardless+of+the+value+of+$something
?>|code-block|syntax|javascript|1450733|然后，您还可以用另一种语法编写if+-+else：|1450734|<?php
if+($something):
+++echo+'one+conditional+line+of+code';
+++echo+'another+conditional+line+of+code';
elseif+($somethingElse):
+++echo+'one+conditional+line+of+code';
+++echo+'another+conditional+line+of+code';
else:
+++echo+'one+conditional+line+of+code';
+++echo+'another+conditional+line+of+code';
endif;
?>|1450735|使用替代语法，您也可以退出解析模式，如下所示：|1450736|<?php
if+($something):
?>
one+conditional+line+of+code<br+/>
another+conditional+line+of+code
<?php
else:
+++echo+"it's+value+was:+$value<br+/>\n";
?>
another+conditional+line+of+code
<?php
endif;
?>|1450737|但是这会变得非常混乱，非常快，我不建议使用它(可能除了模板逻辑)。|1450738|为了让它完整：|1450739|<?php
$result+=+$something+?+'something+was+true'+:+'something+was+false';
echo+$result;
?>

equals

<?php
if+($something)+{
+++$result+=+'something+was+true';
}+else+{
+++$result+=+'something+was+false';
}
echo+$result;
?>|1450740|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|12|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$]]|$1|S|3|T|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

you can do if else statements like this:

<pre><code>&lt;?php
if ($something) {
 echo 'one conditional line of code';
 echo 'another conditional line of code';
}


if ($something) echo 'one conditional line of code';

if ($something)
echo 'one conditional line of code';
echo 'a NON-conditional line of code'; // this line gets executed regardless of the value of $something
?&gt;
</code></pre>

 
and then you can also write if - else in an alternate syntax:

<pre><code>&lt;?php
if ($something):
 echo 'one conditional line of code';
 echo 'another conditional line of code';
elseif ($somethingElse):
 echo 'one conditional line of code';
 echo 'another conditional line of code';
else:
 echo 'one conditional line of code';
 echo 'another conditional line of code';
endif;
?&gt;
</code></pre>

 
with the alternate syntax you can also fall out of parsing mode like this:

<pre><code>&lt;?php
if ($something):
?&gt;
one conditional line of code&lt;br /&gt;
another conditional line of code
&lt;?php
else:
 echo "it's value was: $value&lt;br /&gt;\n";
?&gt;
another conditional line of code
&lt;?php
endif;
?&gt;
</code></pre>

But this gets really messy really fast and I won't recommend it's use (except maybe for template-logic).

 
and to make it complete:

<pre><code>&lt;?php
$result = $something ? 'something was true' : 'something was false';
echo $result;
?&gt;

equals

&lt;?php
if ($something) {
 $result = 'something was true';
} else {
 $result = 'something was false';
}
echo $result;
?&gt;
</code></pre>

blocks|key|1450833|text|在PHP中，大括号(不是方括号)是可选的，就像在大多数类似C的语法中一样。也许您正在考虑Perl；对于这种形式的if语法，Perl是必需的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1450834|冒号是PHP支持的另一种控制结构形式。我讨厌它，但有些人(显然，特别是模板系统设计师)喜欢它。|1450835|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Braces (not brackets) are optional in PHP, as in most C-like syntax. Maybe you're thinking of Perl; they're required there, for that form of if syntax.

The colon thing is an alternate control structure form that PHP supports. I hate it, but some people (particularly template system designers, apparently) love it.

blocks|key|1665943|text|更详细一点，大括号是可选的原因是语法看起来像这样：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1665944|if(CONDITION)+BLOCK
[elseif(CONDITION)+BLOCK]
[else+BLOCK]|code-block|syntax|javascript|1665945|块可以是一条语句：|1665946|foo();|1665947|或者它可以是一组用大括号括起来的语句：|1665948|{
++++foo();
++++bar();
}|1665949|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

To go into a little more detail, the reason that the braces are optional is that the syntax looks like:

<pre><code>if(CONDITION) BLOCK
[elseif(CONDITION) BLOCK]
[else BLOCK]
</code></pre>

BLOCK can be a single statement:

<pre><code>foo();
</code></pre>

or it can be a brace-enclosed group of statements:

<pre><code>{
 foo();
 bar();
}
</code></pre>

blocks|key|1450967|text|照我的想法|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1450968|if+($REMOTE_ADDR+==+"")+$ip+=+"no+ip";+else+$ip+=+getHostByAddr($REMOTE_ADDR);|code-block|syntax|javascript|1450969|是有效的，但比以下代码更难阅读：|1450970|if+($REMOTE_ADDR+==+"")+{
++++$ip+=+"no+ip";+
}+else+{
++++$ip+=+getHostByAddr($REMOTE_ADDR);
}|1450971|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

In my opinion

<pre><code>if ($REMOTE_ADDR == "") $ip = "no ip"; else $ip = getHostByAddr($REMOTE_ADDR);
</code></pre>

is valid, but much harder to read than:

<pre><code>if ($REMOTE_ADDR == "") {
 $ip = "no ip"; 
} else {
 $ip = getHostByAddr($REMOTE_ADDR);
}
</code></pre>

blocks|key|1451030|text|brackets+are+needed+to+enclose+what+you+want+to+do+if+the+condition+is+true|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1451031|我想不出有哪种语言需要这样做|unstyled|1451032|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>brackets are needed to enclose what you want to do if the condition is true
</code></pre>

I can't think of any language that requires this

blocks|key|1666088|text|9年过去了，我很惊讶竟然没有人提到ternary+operator|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1666089|$ip+=+($REMOTE_ADDR+==+"")+?+"no+ip"+:+getHostByAddr($REMOTE_ADDR);|code-block|syntax|javascript|1666090|赋值更清晰--因为对于通常的变量赋值，它会引出被赋值的变量。|1666091|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/language.operators.comparison.php^0|H|G|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

9 years on and I'm surprised no-one's mentioned the <a href="http://php.net/manual/en/language.operators.comparison.php" rel="nofollow noreferrer">ternary operator</a>:

<pre><code>$ip = ($REMOTE_ADDR == "") ? "no ip" : getHostByAddr($REMOTE_ADDR);
</code></pre>

Much clearer for assignment IMHO - because it leads out with the variable being assigned to, as for usual variable assignment.

I was just browsing a forum and someone asked about a PHP file they had found on the web. It has several spots like this in the code:

<code>if ($REMOTE_ADDR == "") $ip = "no ip";
else $ip = getHostByAddr($REMOTE_ADDR);</code>

I have always thought brackets are needed to enclose what you want to do if the condition is true. Is there some other alternative, such as if it is on the same line you don't?

There is also another line like this:
<code>if ($action != ""):
mail("$adminaddress","Visitor Comment from YOUR SITE",</code>

My instinct is to say this wouldn't work, but I also don't know if it is an outdated PHP file and it used to work?

PHP conditionals, brackets needed?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我刚刚浏览了一个论坛，有人问起他们在网上找到的一个PHP文件。它在代码中有几个类似的地方：if ($REMOTE_ADDR == "") $ip = "no ip"; else $ip = getHostByAddr($REMOTE_ADDR);我一直认为，如果条件为真，则需要用括号括起您想要做的事情。是否有其他选择，...

问PHP条件，需要括号吗？
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