javascript - Write to CSV file locally with HTML5 -

i wondering whether html5 allows 1 save/write local file within user's file system. i'm asking know html5 can export data client , download csv file example.

if not html5, best approach overwrite contents, or create csv (or other type of file matter) locally within client-side script?

function:

function exportdata() {     var data = '';     (var i=1;i<=2;i++) {         var sep = '';         (var j=1;j<=4;j++) {             data +=  sep + document.getelementbyid(i + '_' + j).value;             sep = ',';         }         data += '\r\n';     }     var exportlink = document.createelement('a');     exportlink.setattribute('href', 'data:text/csv;base64,' + window.btoa(data));     exportlink.appendchild(document.createtextnode('test.csv'));     document.getelementbyid('results').appendchild(exportlink); } 

markup:

<input type="number" id="1_1" value="2">, <input type="number" id="1_2" value="1">, <input type="number" id="1_3" value="4">, <input type="number" id="1_4" value="3"> <br> <input type="number" id="2_1" value="1">, <input type="number" id="2_2" value="2">, <input type="number" id="2_3" value="3">, <input type="number" id="2_4" value="4"> <br> <button onclick="exportdata()">export csv</button> <div id="results"></div> 

demo:

click button link, click link , file. change values, click link again , different file. firefox made me select excel every time open don't know whether that's configuration or general issue.

live demo

reference:

is possible use html5 fanciness export local storage excel?