javascript - Tooltip in title element not working -

i'm trying create tooltip using javascript , bootstrap. problem when try using var t = document.getelementbyid('toolt').title; t = data[x].time; should put title element on html element doesn't.

here's full code:

<i data-toggle="tooltip" class="fa fa-info-circle" id='toolt'></i> <script> // listen output socket.on('output', function(data) {     if(data.length) {         // loop through results         for(var x = 0; x < data.length; x = x + 1) {             var message = document.createelement('div');              var t = document.getelementbyid('toolt').title;                 t = data[x].time;              message.setattribute('class', 'chat-message');             message.textcontent = data[x].name + ': ' + data[x].message;              // append             messages.appendchild(message);             messages.insertbefore(message, info.firstchild);             }         }     }); </script> 

it's becasue assiging new value varaible, not changing property of object/html

 var t = document.getelementbyid('toolt').title;      t = data[x].time; // doing here setting varaible 't' "" // setting data[x].time 

you'd need below code set html property value:

document.getelementbyid('toolt').title = data[x].time; 

if need store html object reason, you'd want

var t = document.getelementbyid('toolt'); t.title = data[x].time;