blocks|key|1416569|text|使用if+($var+===+true)或if+($var)不是风格的问题，而是正确性的问题。因为if+($var)和if+($var+==+true)是一样的。并且==比较不会检查类型。所以1+==+true是真的，但是1+===+true是假的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1416570|entityMap^0|2|I|L|9|1D|9|1N|H|2B|2|2O|9|33|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]|$9|U|A|V|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|G|$]]

Using <code>if ($var === true)</code> or <code>if ($var)</code> is not a question of style but a question of correctness. Because <code>if ($var)</code> is the same as <code>if ($var == true)</code>. And <code>==</code> comparison doesn’t check the type. So <code>1 == true</code> is true but <code>1 === true</code> is false.

blocks|key|1416620|text|当第一个指针在堆积如山的位置0时，===在strstr/stristr中非常有用。如果你不使用===或!==，你的手头可能会有一个bug。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1416621|$str+=+"four+score+and...";
$position+=+strstr($str,'four');
if($position===FALSE)+return+FALSE;|code-block|syntax|javascript|1416622|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

=== is really helpful in strstr/stristr when the first needle is in position 0 in the haystack. If you don't use === or !== you could have a bug on your hands.

<pre><code>$str = "four score and...";
$position = strstr($str,'four');
if($position===FALSE) return FALSE;
</code></pre>

blocks|key|1201594|text|我对PHP的技术内容不是很了解，但在第一种情况下|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1201595|if($variable+===+true)|code-block|syntax|javascript|1201596|$variable必须具有与true完全相同的类型，if语句才为true。换句话说，$variable不仅必须解析为true，而且还必须是一个布尔值。这就是两个操作，值检查和类型检查。|1201597|在第二种情况下|1201598|if($variable)|1201599|$variable只需解析为true即可。因此，只进行值检查。我推断这会使计算机花费更少的时间。|1201600|实际上:速度上的差异可能可以忽略不计。|1201601|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|W|8|@]|9|@]|A|$E|F]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

I'm not really deep into the technical stuff of PHP, but in the first case

<pre><code>if($variable === true)
</code></pre>

$variable has to have the exact same type as true for the if statement to be true. In other words, $variable has not only to resolve to true, but also has to be a boolean. So that's 2 operations, value-checking and type-checking.

In the second case

<pre><code>if($variable)
</code></pre>

$variable only has to resolve to true. So only value checking occurs. I infer that that takes the computer a little less time.

Practically speaking: the differences in speed are probably negligible.

blocks|key|1201658|text|至于速度，我同意Niels的观点，它可能可以忽略不计。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1201659|至于哪条if语句最适合测试，答案可能取决于预期的类型转换和$variable可以具有的值。|1201660|如果$variable使用0和1作为true/false标志，那么If+(+$variable+)或if+(+!$variable+)可以工作，但如果它是一个整数结果，如strpos()，则会遇到问题...如果可能，我建议使用实际的布尔值，而不是0/+1。|1201661|..。也许这将有助于澄清；注释掉$var的变体以查看各种结果。|1201662|<?php

$var+=+true;
$var+=+1;

$var+=+false;
$var+=+0;

if+(+$var+)+{
++++echo+'var+=+true+<br+/>';
}

if+(+$var+===+true+)+{
++++echo+'var+is+a+boolean+and+=+true';
}

if+(+!$var+)+{
++++echo+'var+=+false+<br+/>';
}

if+(+$var+===+false+)+{
++++echo+'var+is+a+boolean+and+=+false';
}|code-block|syntax|javascript|1201663|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|R|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|S|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

As far as speed, I agree with Niels, it's probably negligible.

As far as which if statement is best to test with, the answer probably depends on the expected casting and values $variable can have.

If $variable is using 0 and 1 as a true/false flag then if ( $variable ) or if ( !$variable ) would work, but if it's an integer result as in strpos() you'll run into problems ... if possible, I'd recommend using an actual boolean value rather than 0 / 1.

... maybe this will help clarify; comment out the variations of $var to see the various results.

<pre><code>&lt;?php

$var = true;
$var = 1;

$var = false;
$var = 0;

if ( $var ) {
 echo 'var = true &lt;br /&gt;';
}

if ( $var === true ) {
 echo 'var is a boolean and = true';
}

if ( !$var ) {
 echo 'var = false &lt;br /&gt;';
}

if ( $var === false ) {
 echo 'var is a boolean and = false';
}
</code></pre>

blocks|key|1201695|text|只有一个事实：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1201696|time+php+-r+'$r+=+true;+for($i+=+0;+$i+<+10000000;+$i%2B%2B)+{+if($r+==+true)+{}+}'|offset|length|style|CODE|1201697|time+php+-r+'$r+=+true;+for($i+=+0;+$i+<+10000000;+$i%2B%2B)+{+if($r)+{}+}'|1201698|第二个比第一个快。|1201699|entityMap^0|0|0|27|0|0|1Z|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@$D|P|E|Q|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|U|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|M|$]]

Just a fact:

<code>time php -r '$r = true; for($i = 0; $i &lt; 10000000; $i++) { if($r == true) {} }'</code>

<code>time php -r '$r = true; for($i = 0; $i &lt; 10000000; $i++) { if($r) {} }'</code>

The second one is faster than the first.

I know this question is not really important.. however I've been wondering:

Which of the following IF statements is the best and fastest to use?

<pre><code>&lt;?php

$variable = true;

if($variable === true)
{
 //Something
}

if($variable)
{
 // Something
}


?&gt;
</code></pre>

I know === is to match exactly the boolean value. However is there really any improvement?

PHP IF statement for Boolean values: $var === true vs $var

我知道这个问题并不重要。然而，我一直在想：下面哪一条IF语句是最好、最快的？<?php$variable = true;if($variable === true){ //Something}if($variable){ // Something}?>我知道===将精确地匹配布尔值。然而，真的有什么改进吗？

问用于布尔值的PHP IF语句：$var === true vs $var
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