Question

引证:

$test = array (2+2);
var_dump($test);

随后在课堂内进行同样的审判:

class test {
    public $test = array(2+2);
}

我只想知道,为什么有人会错过教区,也许会怎样解决(在课堂)这种容易使用守则和尽可能干的错误。

Answer 1

你们不能使用声明来初步确定分类领域。它必须是字面的,具有不变的价值。工作是使用建筑工:

class Test {
    public $test;

    public function __construct() {
        $this->test = array(2+2);
    }
}

From the manual:

Class member variables are called "properties". You may also see them referred to using other terms such as "attributes" or "fields", but for the purposes of this reference we will use "properties". They are defined by using one of the keywords public, protected, or private, followed by a normal variable declaration. This declaration may include an initialization, but this initialization must be a constant value--that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

Answer 2

原因是,对某类财产的转让必须是静态申报。不能说是评估的表述。

这是你可以做到的:

public $test = array(4); // static assignment
public $test =  some string ; // static assignment
public $test = strtoupper(   some string   ); // invalid, expression
public $test = $global_variable; // invalid, not a constant expression
public $test = time(); // invalid, an expression

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