Vanishes the text content of elements with a certain class in some milliseconds.

vanish_text.js

// Vanishes the text content of elements with a certain class in some milliseconds
var vanishByClassName = (function() {

    // Returns a random integer [min, max)
    var getRandomInt = function(min, max) {
        return Math.floor(Math.random() * (max - min)) + min;
    };

    // Returns a string with a swapped out character
    var replaceStringCharacter = function(string, index, character) {
        return string.substring(0,index) + character + string.substring(index+1);
    };

    // Returns an array of length with sequential numbers
    var arrayOfSequentialNumbers = function(length) {
        return Array.apply(null, {length: length}).map(Number.call, Number);
    };

    // Returns a copy of an array spliced
    var splice = function(array, index, count) {
        array = array.slice();
        count !== void 0 ? array.splice(index, count) : array.splice(index, count);
        return array;
    };

    // Vanishes the text of an element at a step of a time iteration
    var vanishElement = function(element, timeIteration, arrayOfIndexes) {
        arrayOfIndexes = arrayOfIndexes || arrayOfSequentialNumbers(element.textContent.length);
        var index = getRandomInt(0,arrayOfIndexes.length);
        var spot = arrayOfIndexes[index];
        arrayOfIndexes.splice(index, 1);
        element.textContent = replaceStringCharacter(element.textContent, spot, ' ');
        if (arrayOfIndexes.length > 0) {
            setTimeout(vanishElement.bind(null, element, timeIteration, arrayOfIndexes), timeIteration);
        }
    };

    // Vanishes the text in an array of elements simultaneously in some milliseconds
    var vanishElements = function(elements, milliseconds) {
        if (elements.length === 0) {
            return;
        }
        vanishElement(elements[0], milliseconds/elements[0].textContent.length);
        vanishElements(splice(elements, 0, 1), milliseconds);
    }

    // Vanishes the text content with a certain class in some milliseconds
    return function(className, milliseconds) {
        return vanishElements([].slice.call(document.getElementsByClassName(className)), milliseconds);
    };

}());