如何将字符串转换为布尔值php

「爱情、让人受尽委屈。」 2022-11-29 05:37 215阅读 0赞

本文翻译自：[How to convert string to boolean php][]

*How can I convert string to `boolean` ?* **如何将字符串转换为`boolean` ？**

$string = 'false';
    
    $test_mode_mail = settype($string, 'boolean');
    
    var_dump($test_mode_mail);
    
    if($test_mode_mail) echo 'test mode is on.';

*it returns,* **它回来了，**

> *boolean true* **布尔值为true**

*but it should be `boolean false` .* **但它应该是`boolean false` 。**

--------------------

### \#1楼 ###

参考：[https://stackoom.com/question/uMEt/如何将字符串转换为布尔值php][https_stackoom.com_question_uMEt_php]

--------------------

### \#2楼 ###

*This method was posted by @lauthiamkok in the comments.* **这个方法由@lauthiamkok在评论中发布。** *I'm posting it here as an answer to call more attention to it.* **我在这里发布它作为回答更多关注它的答案。**

*Depending on your needs, you should consider using `filter_var()` with the `FILTER_VALIDATE_BOOLEAN` flag.* **根据您的需要，您应该考虑将`filter_var()`与`FILTER_VALIDATE_BOOLEAN`标志一起使用。**

filter_var(    'true', FILTER_VALIDATE_BOOLEAN); // true
    filter_var(         1, FILTER_VALIDATE_BOOLEAN); // true
    filter_var(       '1', FILTER_VALIDATE_BOOLEAN); // true
    filter_var(      'on', FILTER_VALIDATE_BOOLEAN); // true
    filter_var(     'yes', FILTER_VALIDATE_BOOLEAN); // true
    
    filter_var(   'false', FILTER_VALIDATE_BOOLEAN); // false
    filter_var(         0, FILTER_VALIDATE_BOOLEAN); // false
    filter_var(       '0', FILTER_VALIDATE_BOOLEAN); // false
    filter_var(     'off', FILTER_VALIDATE_BOOLEAN); // false
    filter_var(      'no', FILTER_VALIDATE_BOOLEAN); // false
    filter_var('asdfasdf', FILTER_VALIDATE_BOOLEAN); // false
    filter_var(        '', FILTER_VALIDATE_BOOLEAN); // false
    filter_var(      null, FILTER_VALIDATE_BOOLEAN); // false

--------------------

### \#3楼 ###

*Other answers are over complicating things.* **其他答案是复杂的事情。** *This question is simply **logic** question.* **这个问题只是逻辑问题。** *Just get your statement right.* **只是让你的陈述正确。**

$boolString = 'false';
    $result = 'true' === $boolString;

*Now your answer will be either* **现在你的答案也是**

*  *`false` , if the string was `'false'` ,* **`false` ，如果字符串是`'false'` ，**
 *  *or `true` , if your string was `'true'` .* **或者`true` ，如果你的字符串是`'true'` 。**

*I have to note that `filter_var( $boolString, FILTER_VALIDATE_BOOLEAN );`* **我要注意`filter_var( $boolString, FILTER_VALIDATE_BOOLEAN );`** *still will be a better option **if** you need to have strings like `on/yes/1` as alias for `true` .* **如果您需要像`on/yes/1`这样的字符串作为`true`别名， 那么仍然是一个更好的选择。**

--------------------

### \#4楼 ###

*You can use settype method too!* **你也可以使用settype方法！**

*SetType($var,"Boolean") Echo $var //see 0 or 1* **SetType（$ var，“Boolean”）Echo $ var //参见0或1**

--------------------

### \#5楼 ###

function stringToBool($string){
        return ( mb_strtoupper( trim( $string)) === mb_strtoupper ("true")) ? TRUE : FALSE;
    }

*or* **要么**

function stringToBool($string) {
        return filter_var($string, FILTER_VALIDATE_BOOLEAN);
    }

--------------------

### \#6楼 ###

*When working with JSON, I had to send a Boolean value via `$_POST` .* **使用JSON时，我必须通过`$_POST`发送一个布尔值。** *I had a similar problem when I did something like:* **当我做了类似的事情时，我遇到了类似的问题：**

if ( $_POST['myVar'] == true) {
        // do stuff;
    }

*In the code above, my Boolean was converted into a JSON string.* **在上面的代码中，我的布尔值被转换为JSON字符串。**

*To overcome this, you can decode the string using `json_decode()` :* **要解决此问题，您可以使用`json_decode()`解码字符串：**

//assume that : $_POST['myVar'] = 'true';
     if( json_decode('true') == true ) { //do your stuff; }

*(This should normally work with Boolean values converted to string and sent to the server also by other means, ie, other than using JSON.)* **（这通常应该使用转换为字符串的布尔值并通过其他方式发送到服务器，即使用JSON以外的其他方式。）**

[How to convert string to boolean php]: https://oldbug.net/q/uMEt/How-to-convert-string-to-boolean-php
[https_stackoom.com_question_uMEt_php]: https://stackoom.com/question/uMEt/%E5%A6%82%E4%BD%95%E5%B0%86%E5%AD%97%E7%AC%A6%E4%B8%B2%E8%BD%AC%E6%8D%A2%E4%B8%BA%E5%B8%83%E5%B0%94%E5%80%BCphp