Throttling is a means by which we can limit the number of times a function can be called in a given period.

throttle.js

// Throttling is a means by which we can limit the number of times a function can be called in a given period.
// Throttling is good for reducing mousemove events to a lesser, manageable rate, for instance.
// See e.g: https://remysharp.com/2010/07/21/throttling-function-calls
function throttle(fn, delay, options) {
    'use strict';

    delay   || (delay = 250);
    options || (options = {});

    var timeout,
        result,
        previous = 0;

    return function() {
        var now = new Date();
        if (!previous && options.leading === false) previous = now;

        var remaining = delay - (now - previous),
            context = options.scope || this,
            args = arguments,

            later = function() {
                previous = options.leading ? new Date() : 0;
                timeout = null;
                result = fn.apply(context, args);
            };

        if (remaining <= 0) {
            clearTimeout(timeout);
            previous = now;
            result = fn.apply(context, args);
        } 
        else if (!timeout) {
            timeout = setTimeout(later, remaining);
        }
        return result;
    };
};


(function(){
    var i = 0, 
        n = 0,
        f = throttle( function(x) { ++n; console.log("f(" + x + ") # " + n); }, 250);

    var t = setInterval( function () { 
        f(i);
        if(++i == 200) {
            clearInterval(t);
            console.log("throttle executed " + n + " times in " + i*10 + "ms");
        }

    }, 10);
})();