Typing Text Effect In Javascript

Most of the time we need to create a effect just like typing text in web page but don't know how to do such task through javascript.
 
This article is for creating typing effect for given text through javascript, below is auto started, manual through started through button click demo is given below.

Demo Text :

Typing Text Effect In Javascript Hey! This is a demo article only for showing how typing text works, through javascript.

You can simply use this code by adding this javascript code and place your html as the given place or you can add more block like this just to need create more instance of TypingText Class.

<script type="text/javascript">

/****Class Defination****/

function TypingText (element, interval, cursor, finishedCallback) {

    if ((typeof document.getElementById == "undefined") || (typeof element.innerHTML == "undefined")) {

        this.running = true;

        return;

    }

    this.element = element;

    this.finishedCallback = (finishedCallback ? finishedCallback : function () { return; });

    this.interval = (typeof interval == "undefined" ? 100 : interval);

    this.origText = this.element.innerHTML;

    this.unparsedOrigText = this.origText;

    this.cursor = (cursor ? cursor : "");

    this.currentText = "";

    this.currentChar = 0;

    this.element.typingText = this;

    if (this.element.id == "") this.element.id = "typingtext" + TypingText.currentIndex++;

    TypingText.all.push(this);

    this.running = false;

    this.inTag = false;

    this.tagBuffer = "";

    this.inHTMLEntity = false;

    this.HTMLEntityBuffer = "";

}

/**** Static Valiables ****/

TypingText.all = new Array();

TypingText.currentIndex = 0;

/*** Static Fuction Add ***/

TypingText.runAll = function () {

    for (var i = 0; i < TypingText.all.length; i++) TypingText.all[i].run();

}

/*** Instance Fuction Add ***/

TypingText.prototype.run = function () {

    if (this.running) return;

    if (typeof this.origText == "undefined") {

        setTimeout("document.getElementById('" + this.element.id + "').typingText.run()", this.interval);

        return;

    }

    if (this.currentText == "") this.element.innerHTML = "";

    if (this.currentChar < this.origText.length) {

        if (this.origText.charAt(this.currentChar) == "<" && !this.inTag) {

            this.tagBuffer = "<";

            this.inTag = true;

            this.currentChar++;

            this.run();

            return;

        } else if (this.origText.charAt(this.currentChar) == ">" && this.inTag) {

            this.tagBuffer += ">";

            this.inTag = false;

            this.currentText += this.tagBuffer;

            this.currentChar++;

            this.run();

            return;

        } else if (this.inTag) {

            this.tagBuffer += this.origText.charAt(this.currentChar);

            this.currentChar++;

            this.run();

            return;

        } else if (this.origText.charAt(this.currentChar) == "&" && !this.inHTMLEntity) {

            this.HTMLEntityBuffer = "&";

            this.inHTMLEntity = true;

            this.currentChar++;

            this.run();

            return;

        } else if (this.origText.charAt(this.currentChar) == ";" && this.inHTMLEntity) {

            this.HTMLEntityBuffer += ";";

            this.inHTMLEntity = false;

            this.currentText += this.HTMLEntityBuffer;

            this.currentChar++;

            this.run();

            return;

        } else if (this.inHTMLEntity) {

            this.HTMLEntityBuffer += this.origText.charAt(this.currentChar);

            this.currentChar++;

            this.run();

            return;

        } else {

            this.currentText += this.origText.charAt(this.currentChar);

        }

        this.element.innerHTML = this.currentText;

        this.element.innerHTML += (this.currentChar < this.origText.length - 1 ? (typeof this.cursor == "function" ? this.cursor(this.currentText) : this.cursor) : "");

        this.currentChar++;

        setTimeout("document.getElementById('" + this.element.id + "').typingText.run()", this.interval);

    } else {

        this.currentText = "";

        this.currentChar = 0;

        this.running = false;

        this.finishedCallback();

    }

}

</script>

<div id="divTypingtext">

    <%--Place your text here--%>

</div>

<p id="pTypingtext">

    <%--Place your text here--%>

</p>

<input type="button" id="btnShow" onclick='TypingText.runAll();' value="Start Typing Text"/>

 

<script type="text/javascript">

  
new TypingText(document.getElementById("divTypingtext"), 100, "_", TaskCompleted1);

  
new TypingText(document.getElementById("pTypingtext"), 100, function (i) { var ar = new Array("_", " "); return " " + ar[i.length % ar.length]; }, TaskCompleted2);

function TaskCompleted1() {

    alert("Task 1 Completed")

}

function TaskCompleted2() {

    alert("Task 2 Completed")

}

</script>

Here you can also use manual cursor as you want, just to change the function of cursor some manual cursor function given below.

function (i) { var ar = new Array("_", " "); return " " + ar[i.length % ar.length]; }