php全局配置和应用程序中的设置

Question

I have a file 'config.php' which Is included at the beginning of my program (see below) Main file runs require 'config.php';

config.php

<?
global $config;
$config['tblist'] = 'pending'; 
$config['tbdone'] = 'checked';
$config['checkfreq'] = 24;
?>

I then create a new page object

$page = new Page($name,$source);

One of the functions in that page object I want to be able to grab stuff from the config but it doesn't seem to be able to reference to $config. Have I put global $config; in the right place?

Answer 1

When making references to global variables in functions, you must declare them as global:

global $config;

This is also interesting: http://me.veekun.com/blog/2012/04/09/php-a-fractal-of-bad-design/

There is no way to declare a variable. Variables that don’t exist are created with a null value when first used.

Global variables need a global declaration before they can be used. This is a natural consequence of the above, so it would be perfectly reasonable, except that globals can’t even be read without an explicit declaration—PHP will quietly create a local with the same name, instead. I’m not aware of another language with similar scoping issues.

To be fair it will also throw a Notice if you've got them enabled.