How to read and write into file using JavaScript?

Question

Can anybody give some sample code to read and write a file using JavaScript?

Answer 1

For Firefox:

var file = Components.classes["@mozilla.org/file/local;1"].
       createInstance(Components.interfaces.nsILocalFile);
file.initWithPath("/home");

See https://developer.mozilla.org/en-US/docs/Code_snippets/File_I_O

For others, check out the TiddlyWiki app to see how it does it.