jQuery counter to count up to a target number

I ended up creating my own plugin. Here it is in case this helps anyone:

(function($) {
    $.fn.countTo = function(options) {
        // merge the default plugin settings with the custom options
        options = $.extend({}, $.fn.countTo.defaults, options || {});
        
        // how many times to update the value, and how much to increment the value on each update
        var loops = Math.ceil(options.speed / options.refreshInterval),
            increment = (options.to - options.from) / loops;
        
        return $(this).each(function() {
            var _this = this,
                loopCount = 0,
                value = options.from,
                interval = setInterval(updateTimer, options.refreshInterval);
            
            function updateTimer() {
                value += increment;
                loopCount++;
                $(_this).html(value.toFixed(options.decimals));
                
                if (typeof(options.onUpdate) == 'function') {
                    options.onUpdate.call(_this, value);
                }
                
                if (loopCount >= loops) {
                    clearInterval(interval);
                    value = options.to;
                    
                    if (typeof(options.onComplete) == 'function') {
                        options.onComplete.call(_this, value);
                    }
                }
            }
        });
    };
    
    $.fn.countTo.defaults = {
        from: 0,  // the number the element should start at
        to: 100,  // the number the element should end at
        speed: 1000,  // how long it should take to count between the target numbers
        refreshInterval: 100,  // how often the element should be updated
        decimals: 0,  // the number of decimal places to show
        onUpdate: null,  // callback method for every time the element is updated,
        onComplete: null,  // callback method for when the element finishes updating
    };
})(jQuery);

Here's some sample code of how to use it:

<script type="text/javascript"><!--
    jQuery(function($) {
        $('.timer').countTo({
            from: 50,
            to: 2500,
            speed: 1000,
            refreshInterval: 50,
            onComplete: function(value) {
                console.debug(this);
            }
        });
    });
//--></script>

<span class="timer"></span>

View the demo on JSFiddle: http://jsfiddle.net/YWn9t/

Don't know about plugins but this shouldn't be too hard:

;(function($) {        
     $.fn.counter = function(options) {
        // Set default values
        var defaults = {
            start: 0,
            end: 10,
            time: 10,
            step: 1000,
            callback: function() { }
        }
        var options = $.extend(defaults, options);            
        // The actual function that does the counting
        var counterFunc = function(el, increment, end, step) {
            var value = parseInt(el.html(), 10) + increment;
            if(value >= end) {
                el.html(Math.round(end));
                options.callback();
            } else {
                el.html(Math.round(value));
                setTimeout(counterFunc, step, el, increment, end, step);
            }
        }            
        // Set initial value
        $(this).html(Math.round(options.start));
        // Calculate the increment on each step
        var increment = (options.end - options.start) / ((1000 / options.step) * options.time);            
        // Call the counter function in a closure to avoid conflicts
        (function(e, i, o, s) {
            setTimeout(counterFunc, s, e, i, o, s);
        })($(this), increment, options.end, options.step);
    }
})(jQuery);

Usage:

$('#foo').counter({
    start: 1000,
    end: 4500,
    time: 8,
    step: 500,
    callback: function() {
        alert("I'm done!");
    }
});

Example:

http://www.ulmanen.fi/stuff/counter.php

I guess the usage is self-explanatory; in this example, the counter will start from 1000 and count up to 4500 in 8 seconds in 500ms intervals, and will call the callback function when the counting is done.

You can use the jQuery animate function

$({ countNum: 0 }).animate({ countNum: 10 }, {
  duration: 10000, // tune the speed here
  easing: 'linear',
  step: function() {
    // What todo on every count
    console.log(this.countNum);
  },
  complete: function() {
    console.log('finished');
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

I've created the tiniest code to do exactly that. It's not only for counting but for any task that needs to run in a given time. (let's say, do something for 5 seconds):

• Codepen Demo Page

• Do-In: Github Project (super lightweight tiny script)

Demo:

var step = function(t, elapsed){
    // easing 
    t = t*t*t;

    // calculate new value
    var value = 300 * t; // will count from 0 to 300

    // limit value ("t" might be higher than "1")
    if( t > 0.999 )
        value = 300;

    // print value (converts it to an integer)
    someElement.innerHTML = value|0;
};

var done = function(){
    console.log('done counting!');
};


// Do-in settings object
var settings = {
    step     : step,
    duration : 3,
    done     : done,
    fps      : 24 // optional. Default is requestAnimationFrame
};

// initialize "Do-in" instance 
var doin = new Doin(settings);