How do you take the following and substitue part of the file path as a variable?
require_once $_SERVER['DOCUMENT_ROOT'] . '/directory1/directory2/directory3/file.php';
I want to substiture directory2 with a variable $dir2. Simply inserting the variable as follows does not work?
require_once $_SERVER['DOCUMENT_ROOT'] . '/directory1/$dir2/directory3/file.php';
Thanks.
Basic php syntax: strings quoted with ' do not interpolate variables. Use a "-quoted string instead:
require_once $_SERVER['DOCUMENT_ROOT'] . "/directory1/$dir2/directory3/file.php";
^--- ^---
or use string concatenation:
require_once $_SERVER['DOCUMENT_ROOT'] . '/directory1/' . $dir2 . '/directory3/file.php';
Use " will parse the variable.
"/directory1/$dir2/directory3/file.php"
And instead of depending $_SERVER['DOCUMENT_ROOT'], you should do something like diranme(__FILE__) or __DIR__ (>= 5.3) to define a root dir.
There are two ways to do this in PHP.
require_once $_SERVER['DOCUMENT_ROOT'] . '/directory1/'.$dir2.'/directory3/file.php';
Or
require_once $_SERVER['DOCUMENT_ROOT'] . "/directory1/$dir2/directory3/file.php";
The difference is in using ' or " for strings. When using ' You need to concatenate variables as in the example and as You already did with $_SERVER['DOCUMENT_ROOT']. When using ", You can put the variables in strings "as is" or even do something like this (useful with arrays):
require_once $_SERVER['DOCUMENT_ROOT'] . "/directory1/{$_SERVER["HTTP_HOST"]}/directory3/file.php";
Single quotes prevent variable substitution. Use double quotes:
require_once $_SERVER['DOCUMENT_ROOT'] . "/directory1/$dir2/directory3/file.php";
