javascript setInterval only work once?

Question

i need to show current time in html code, but the javascript code only work once?

 $(document).ready(function () {
     function updateClock(ele){
         var current_time = new Date();
         var current_time_str = current_time.toLocaleTimeString();
         ele.text(current_time_str);
         console.log(current_time_str);
     }

   setInterval(updateClock($('#clock')) , 1000 );
 })

It's work different some others languages like C,Object-C or Python, it's so misleading for me.

Related: [How can I pass a parameter to a setTimeout() callback?](https://stackoverflow.com/questions/1190642/how-can-i-pass-a-parameter-to-a-settimeout-callback) — Jonathan Lonowski, May 28 '18 at 06:57

Nina Scholz · Accepted Answer · 2018-05-28T07:22:28.657

3

You need to wrap the calling part in a function, because it is called only once and returns undefined as calling value.

setInterval(() => updateClock($('#clock')), 1000);

Another possibillity is to use the third and following arguments of setInterval

setInterval(updateClock, 1000, $('#clock'));

edited May 28 '18 at 07:22

answered May 28 '18 at 06:54

Nina Scholz

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score 0 · Answer 2 · answered May 28 '18 at 07:13

Put the updateClock inside setInterval callback function

$(document).ready(function() {
  function updateClock(ele) {
    var current_time = new Date();
    var current_time_str = current_time.toLocaleTimeString();
    ele.text(current_time_str);
  }

  setInterval(function() {
    updateClock($('#clock'))
  }, 1000);
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="clock"></div>

javascript setInterval only work once?

2 Answers2