Question

PHP中文件包含：/与.

在使用include时，第一，如何包含子文件？第二，如何包含上级文件？
如何使用：/与.
请区别：
设
index.php中此代码：include("fckeditor/fckeditor.php")是何意？
include("/fckeditor/fckeditor.php")是何意？
include("../fckeditor/fckeditor.php")是何意？
include("./fckeditor/fckeditor.php")是何意？

Answer 1

比如一个网站目录文件夹为“www” www下有 fckeditor文件夹和images文件夹。index.php为www下的文件和fckeditor、images为同一级别。

include("fckeditor/fckeditor.php") index.php包含www下的的fckeditor/fckeditor.php。fckeditor文件夹和index.php是同一级。

include("/fckeditor/fckeditor.php") 包含网站根目录下的/fckeditor/fckeditor.php。不管index.php在网站的什么位置，都是包含网站根目录下/fckeditor/fckeditor.php这个文件。

include("../fckeditor/fckeditor.php") 假如index.php文件在images文件夹下，包含的是fckeditor/fckeditor.php。“../”向上一级的意思。
include("./fckeditor/fckeditor.php") 这个没搞明白。

Answer 2

你的第1,2,4中的写法其实是一样的，标识fckeditor文件夹和index.php处于同一目录下，而第3中写法说明包含index.php的文件夹和fckeditor处于同一目录下。

Answer 3

include("fckeditor/fckeditor.php")表示引入在fckeditor文件夹下的fckeditor.php文件：
include("../fckeditor/fckeditor.php")表示引入在上一级文件下的fckeditor文件夹里的fckeditor.php文件：
include("./fckeditor/fckeditor.php")的意思和include("fckeditor/fckeditor.php")是一样的！！！

Answer 4

就是把文件包含进来

include("fckeditor/fckeditor.php")
include("./fckeditor/fckeditor.php")

表示包含当前目录下的 fckeditor/fckeditor.php 文件

include("../fckeditor/fckeditor.php")
表示 包含上一级目录下的 fckeditor/fckeditor.php 文件

include("/fckeditor/fckeditor.php")
表示包含根目录下的 fckeditor/fckeditor.php 的文件

差别就是 相对路径 绝对路径