php 检查变量是否返回 true
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Check if variable returns true
提问by AlxVallejo
I want to echo 'success' if the variable is true. (I originally wrote "returns true" which only applies to functions.
如果变量为真，我想回显“成功”。（我最初写的“返回真”只适用于函数。
$add_visits = add_post_meta($id, 'piwik_visits', $nb_visits, true);
if($add_visits == true){
echo 'success';
}
Is this the equivalent of
这是否相当于
$add_visits = add_post_meta($id, 'piwik_visits', $nb_visits, true);
if($add_visits){
echo 'success';
}
Or does $add_visits exist whether it is 'true' or 'false';
或者 $add_visits 是否存在，无论它是 'true' 还是 'false'；
回答by usumoio
You might want to consider:
您可能需要考虑：
if($add_visits === TRUE){
echo 'success';
}
This will check that your value is TRUE and of type boolean, this is more secure. As is, your code will echo success in the event that $add_visits were to come back as the string "fail" which could easily result from your DB failing out after the request is sent.
这将检查您的值是否为 TRUE 和布尔类型，这更安全。照原样，如果 $add_visits 作为字符串“fail”返回，则您的代码将回显成功，这很容易因您的数据库在发送请求后失败而导致。
回答by Guillaume Poussel
Testing $var == trueis the same than just testing $var.
测试$var == true与测试相同$var。
You can read this SO questionon comparison operator. You can also read PHP manualon this topic.
您可以在比较运算符上阅读此 SO 问题。您还可以阅读有关此主题的PHP 手册。
Note: a variable does not returntrue. It istrue, or it evaluatesto true. However, a function returnstrue.
注意：变量不会返回true。它是true，或者它的计算结果是true。但是，函数返回true.
回答by Jezen Thomas
They're the same.
他们是一样的。
This...
这个...
if ($add_visits == true)
echo 'success';
...Is the same as:
...是相同的：
if ($add_visits)
echo 'success';
In the same fashion, you can also test if the condition is false like this:
以同样的方式，您还可以像这样测试条件是否为假：
if (!$add_visits)
echo "it's false!";
回答by Flemming
The most secure way is using php validation. In case of a ajax post to php:
最安全的方法是使用 php 验证。如果是 ajax post 到 php：
$isTrue=filter_var($_POST['isTrue'], FILTER_VALIDATE_BOOLEAN);
回答by Ben
Yeah, that would work fine.
是的，那会很好用。
//true
if($variable) echo "success";
if($variable == true) echo "success";
//false
if(!$variable) echo "failure";
if($variable == false) echo "failure";
回答by Dilvish5
if($add_visits === TRUE)
should do the trick.
应该做的伎俩。
回答by cdmo
if (isset($add_visits) && $add_visits === TRUE){
echo 'success';
}
Might seem redundant, but PHP will throw a Noticeif $add_visitsisn't set. This would be the safest way to test if a variable is true.
可能看起来多余，但 PHP 会抛出一个Noticeif$add_visits未设置。这将是测试变量是否为真的最安全方法。
