无法在类中将PDO对象初始化为属性 [英] Can't initialize a PDO object in a class as a property

问题描述

可能重复：

将属性声明为对象？

class core
{
 public $dbh = new PDO("mysql:dbname=newdbnaem;host=1.1.1.1:1111", "owner", "passwordlulz");
 function superman() {}
}

函数的结束标记。

推荐答案

只有常量值可以用作类属性的初始值。在构造函数中执行：

Only constant values can be used as initializers for class properties. Do it in the constructor:

class core {

    public $dbh = null;

    public function __construct() {
        $this->dbh = new PDO("mysql:dbname=newdbnaem;host=1.1.1.1:1111", "owner", "passwordlulz");
    }

}

这个声明可以包括一个初始化，但是这个初始化必须是一个常量值 - 也就是说，它必须能够在编译时被评估，并且不能依赖运行时信息来进行评估。

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.

http://www.php.net/manual/en/language.oop5.properties.php

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