Animate changing words width

Question

I have a sentence where I fade in one word and replace it with another from an array. However, since the words all vary in length, the sentence width abruptly changes and it results in a choppy transition.
How can I animate the width change? I tried adding a transition to the container of the sentence in css but that didn't work. I applied the transition as 1.5s all linear, so it should be animating the width as well as everything else whenever there is change. Any ideas?

$(function() {
  var hello = ['dynamic', 'a', 'aklsjdlfajklsdlkf', 'asdf'];
  var used = ['dynamic'];
  var greeting = $('#what');
  var item;

  function hey() {

    item = hello[Math.floor(Math.random() * hello.length)];
    if (hello.length != used.length) {
      while (jQuery.inArray(item, used) != -1) {
        item = hello[Math.floor(Math.random() * hello.length)];
      }
      used.push(item);
    } else {
      used.length = 0;
      item = hello[Math.floor(Math.random() * hello.length)];
      used.push(item);
    }
    greeting.html(item);
    greeting.animate({
      "opacity": "1"
    }, 1500);
  }

  window.setInterval(function() {
    greeting.animate({
      "opacity": "0"
    }, 1500);
    setTimeout(hey, 1500)
  }, 5000);

});

#sentence {
  transition: 1.5s all linear;
}

#what {
  font-style: italic;
  text-decoration: underline;
  color: red;
}

<p id="sentence">
  This is a sentence that has <span id="what">dynamic</span> text that alters width.
</p>

<script src="//ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>

EDIT: Sorry if I was unclear, I only want to fade out the word, not the entire sentence. I'm trying to animate the width to fit the new word. I don't want to change/add any elements, just solve with the current tags in place.

Answer 1

function dataWord () {

  $("[data-words]").attr("data-words", function(i, d){
    var $self  = $(this),
        $words = d.split("|"),
        tot    = $words.length,
        c      = 0; 

    // CREATE SPANS INSIDE SPAN
    for(var i=0; i<tot; i++) $self.append($('<span/>',{text:$words[i]}));

    // COLLECT WORDS AND HIDE
    $words = $self.find("span").hide();

    // ANIMATE AND LOOP
    (function loop(){
      $self.animate({ width: $words.eq( c ).width() });
      $words.stop().fadeOut().eq(c).fadeIn().delay(1000).show(0, loop);
      c = ++c % tot;
    }());
    
  });

}

// dataWord(); // If you don't use external fonts use this on DOM ready; otherwise use:
$(window).on("load", dataWord);

p{text-align: center;font-family: 'Open Sans Condensed', sans-serif;font-size: 2em;}

/* WORDS SWAP */
[data-words]{
  vertical-align: top;
  position: static;
}
[data-words] > span{
  position: absolute;
  color: chocolate;
}

<link href='http://fonts.googleapis.com/css?family=Open+Sans+Condensed:300' rel='stylesheet' type='text/css'>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<p>
  We provide
  <span data-words="code|solutions|design"></span>
  for your business.
</p>

<p>
  You ordered
  <span data-words="1|3|28"></span>
  <b>big</b>
  <span data-words="salad|macs|chips"></span>
</p>

Answer 2

When you set new word for your sentence, you can save #what width and then make an animation with this width too. Like this:

// declare as global variable and update when you set new word
var width = greeting.css('width'); 
// animation
greeting.animate({
            "opacity": "0", "width": width
        }, 1500, function(){
        });

Answer 3

I have had the same problem and went with a different approach, not fading but typing: jsfiddle demo

function type($el, text, position) {
    if (text.length >= position) {
        var rchars = 'qbvol'; // typo chars
        if (position % 3 == 0 && Math.random() > .85) { // insert typo!
            var typo;
            var chr = text.substr(position, 1);
            if (chr == chr.toUpperCase()) { typo = chr.toLowerCase(); }
            else { typo = rchars.substr(Math.floor(Math.random() * rchars.length), 1); }
            $el.text(text.substring(0, position - 1) + typo + '_');
            setTimeout(function() { type($el, text, position - 1); }, 200)
        }
        else {
            $el.text(text.substring(0, position) + '_');
            setTimeout(function() { type($el, text, position + 1); }, 150)
        }
    }
    else {
        setTimeout(function() { $el.text(text); }, 400)
    }
}

It basically inserts your new text on the page, with a nice caret and typo to make it look like someone is typing it.