How to open a local disk file with JavaScript?

Question

I tried to open file with

window.open(\"file:///D:/Hello.txt\");

The browser does not allow opening a local file this way, probably for sec

Answer 1

Javascript cannot typically access local files in new browsers but the XMLHttpRequest object can be used to read files. So it is actually Ajax (and not Javascript) which is reading the file.

If you want to read the file abc.txt, you can write the code as:

var txt = '';
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function(){
  if(xmlhttp.status == 200 && xmlhttp.readyState == 4){
    txt = xmlhttp.responseText;
  }
};
xmlhttp.open("GET","abc.txt",true);
xmlhttp.send();

Now txt contains the contents of the file abc.txt.