将CSS选择器与：first-child结合使用(Combining CSS Selectors with :first-child)

 在您的示例中，只有$this->config是一个对象。 属性是数组，因此您将使用： 
 
$this->config->reCaptcha['reCaptchaSecretKey']
 
 该对象如下所示： 
 
stdClass Object
(
    [host] => Array
        (
            [URL] => https://thomas-smyth.co.uk
        )

    [dbconfig] => Array
        (
            [DBHost] => localhost
            [DBPort] => 3306
            [DBUser] => thomassm_sqlogin
            [DBPassword] => SQLLoginPassword1234
            [DBName] => thomassm_CadetPortal
        )

    [reCaptcha] => Array
        (
            [reCaptchaURL] => https://www.google.com/recaptcha/api/siteverify
            [reCaptchaSecretKey] => IWouldNotBeSecretIfIPostedItHere
        )

)
 
 要拥有JSON编码然后解码的所有对象： 
 
$this->config = json_decode(json_encode($this->config));

In your example only $this->config is an object. The properties are arrays, so you would use:
 
$this->config->reCaptcha['reCaptchaSecretKey']
 
The object looks like this:
 
stdClass Object
(
    [host] => Array
        (
            [URL] => https://thomas-smyth.co.uk
        )

    [dbconfig] => Array
        (
            [DBHost] => localhost
            [DBPort] => 3306
            [DBUser] => thomassm_sqlogin
            [DBPassword] => SQLLoginPassword1234
            [DBName] => thomassm_CadetPortal
        )

    [reCaptcha] => Array
        (
            [reCaptchaURL] => https://www.google.com/recaptcha/api/siteverify
            [reCaptchaSecretKey] => IWouldNotBeSecretIfIPostedItHere
        )

)
 
To have all objects you could JSON encode and then decode:
 
$this->config = json_decode(json_encode($this->config));