How can I show dots ("...") in a span with hidden overflow?

If you are using text-overflow:ellipsis, the browser will show the contents whatever possible within that container. But if you want to specifiy the number of letters before the dots or strip some contents and add dots, you can use the below function.

function add3Dots(string, limit)
{
  var dots = "...";
  if(string.length > limit)
  {
    // you can also use substr instead of substring
    string = string.substring(0,limit) + dots;
  }
 
    return string;
}

call like

add3Dots("Hello World",9);

outputs

Hello Wor...

See it in action here

function add3Dots(string, limit)
{
  var dots = "...";
  if(string.length > limit)
  {
    // you can also use substr instead of substring
    string = string.substring(0,limit) + dots;
  }

    return string;
}



console.log(add3Dots("Hello, how are you doing today?", 10));

For this you can use text-overflow: ellipsis; property. Write like this

span {
    display: inline-block;
    width: 180px;
    white-space: nowrap;
    overflow: hidden !important;
    text-overflow: ellipsis;
}

<span>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book</span>

JSFiddle

I think you are looking for text-overflow: ellipsis in combination with white-space: nowrap

See some more details here