Javascript-1-document.getElementById('') operations

References : w3schools.com
1)http://www.w3schools.com/jsref/default.asp
2)http://www.w3schools.com/js/default.asp

JavaScript is the programming language of HTML and the Web.

obfuscation : Making code unreadable using advanced algorithms.

Change HTML element's content(.innerHTML)

The below code creates a button when clicked on it, the date is displayed in another element with  id="demo", when ie, it changes the element content

<button type="button" onclick="document.getElementById('demo').innerHTML = Date()">
</button>
<p id="demo"></p>

O/P: 

getElementById('demo') : to "find" an HTML element (with id="<<givenId>>") 
.innerHTML : changes/sets the element content

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Change HTML attributes(.src)

The below code changes the src(source) attribute of an img .

<button onclick="document.getElementById('myImage').src='pic_bulbon.gif'"></button>
<img id="myImage" src="pic_bulboff.gif" style="width:100px">

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Change HTML styles(CSS)(.style.) 

<p id="demo">JavaScript</p>
<button type="button" onclick="document.getElementById('demo').style.fontsize="25px">Click Me!</button>


Hide HTML element(CSS)(.style.display="none") 
<p id="demo">JavaScript</p>
<button type="button"  onclick="document.getElementById('demo').style.display="none">Click Me!</button>


Show/Display HTML element(CSS)(.style.display="block") 
<p id="demo">JavaScript</p>

<button type="button"  onclick="document.getElementById('demo').style.display="block">Click Me!</button>

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