Js, DOM, BOM and Browser
Each browser has APIs connected to DOM and BOM objects on the pages so that Js could use them to operate on DOM and BOM：
JS Environment in Chrome Browser：
JS Environment in Node.js：
fs Module
fs.readFile()
method parameters (default format is UTF-8):
example: read file in UTF-8 format, print error(if successful, error == null) or data:
fs.write()
fs.write can only create file can’t create directory
method parameters:
example:
Combined Example
read data in a file, edit and store them in a new file:
Relative Path Problem
in node.js, the relative path is positioned via the directory where the node command is executed but not the directory of the executed Js file:
__dirname
in node.js, __dirname is a variable stores the absolute path of the current Js file:
Use __dirname to solve the relative path problem:
Path Module
path.join(): join multiple path string into a complete path string
path.basename(): return filename string from a path string
path.join()
use path.join() to replace + because the method could resolve ‘./‘ and ‘../‘ in path name
method parameters:
example(attention to ‘../‘ and ‘./‘):
path.basename()
method parameters:
example:
path.extname
method parameters:
example:
