数字计数器 - 制作一个动画计数器

basically, what I am looking for is an animation for digits, a great example would be on this site: http://www.upper-reach.com/

If you scroll down you'll see their 'Builds completed' etc counting up.

How do I do this?

I would appreciate the answers.

You might want to look into this question or you could use the CountUp.JS plugin.

If you want to count the digits you could do something like this when using CountUp.JS:

var myDigit = $(".myDivWithDigits").text();

var options = {
  useEasing : true, 
  useGrouping : true, 
  separator : ',', 
  decimal : '.', 
  prefix : '', 
  suffix : '' 
};
var demo = new CountUp("myTargetElement", 0, myDigit, 0, 2.5, options);
demo.start();

<div class="vc_row wpb_row section vc_inner vc_row-fluid" style='text-align:left;'>
         <div class=" full_section_inner clearfix">
<div class="vc_col-sm-4 wpb_column vc_column_container ">
    <div class="wpb_wrapper">
        <div class="q_counter_holder  center" style=""><span class="counter  random" style="color: #bf1e2e;font-size: 50px;">254,336</span>
                        <span class="separator small" style=""></span>
                        <p class="counter_text" style="font-size: 20px;color: #000000;"></p>
</div>
    </div> 
</div>