Question

I have two classes, class A and class B, and in a function in class A I want to call a function in B, but the it also requires constants from another file. After requiring both the config.php and classB.php files, I am able to create an instance of class B, but when I try to call the function in B, it gives me a warning saying the constant has not been defined.

In config.php:

$constant = 'blah';

Inside class A I have:

function functionA() {
    require_once "config.php";
    require_once "classB.php";
    $b = new B();
    $b -> functionB($constant);
}

The call to function B is giving an error saying $constant is not defined, but when I call new B() there is no problem. Am I doing something wrong?

Answer 1

Aron是对的。在这种情况下，您希望使用include或require。您必须确保您所包含的文件中没有函数或类声明。

这是因为每次调用方法时都不会发生需求，只是第一次调用。随后对该方法的调用将导致未定义的变量错误。

其他热门提示：您可以从包含的文件中返回值，将它们直接分配给变量

a.php只会：

return 'abc';

B.php：

Class B {
    public static function load()
    {
        $x = include 'A.php';
        var_dump($x);
    }
}

我想你的代码应如下所示：

function functionA() {
    require "config.php";
    require_once "classB.php";
    $b = new B();
    $b -> functionB($constant);
}

Answer 2

使用包含'config.php';

的句子

而不是require_once，如果你的config.php文件只有变量声明。

require file inside function PHP

2 个答案: