Javascript Course

Here is a simple JavaScript function that can be used to move a html element to a random direction in page.

click on the code to select it.
//sets a random absolute position to a html element; receives the html element
function moveElmRand(elm){
 elm.style.position ='absolute';
 elm.style.top = Math.floor(Math.random()*90+5)+'%';
 elm.style.left = Math.floor(Math.random()*90+5)+'%';
}

Funny example with auto-moving a button

- In the following example the moveElmRand() function is called when the mouse is over the button. 
<h4>Example auto-moving html element</h4>
<p>Try to click on the following button.</p>

<button id='btn_test'>Catch Me</button>
<script>
//sets a random absolute position to a html element; receives the html element
function moveElmRand(elm){
 elm.style.position ='absolute';
 elm.style.top = Math.floor(Math.random()*90+5)+'%';
 elm.style.left = Math.floor(Math.random()*90+5)+'%';
}

//get the #btn_test
var btn_test = document.querySelector('#btn_test');

//register to call moveElmRand() on mouseenter event to #btn_test
btn_test.addEventListener('mouseenter', function(e){ moveElmRand(e.target);});

//register click to #btn_test
btn_test.addEventListener('click', function(e){ alert('You are Good.');});
</script>

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which HTML5 tag is indicated to be used as container for menu with navigation links in Web site?
<section> <nav> <article>
<nav><ul>
 <li><a href="http://coursesweb.net/css/" title="CSS Course">CSS Course</a></li>
 <li><a href="http://www.marplo.net/jocuri/" title="Flash Games">Flash Games</a></li>
</ul></nav>
Which CSS property shifts an item horizontally to the left or right of where it was?
text-align clear float
.some_class {
  width: 30%;
  float: left;
}
Click on the Math object method which returns x, rounded downwards to the nearest integer.
Math.ceil(x) Math.abs(x) Math.floor(x)
var num = 12.34567;
num = Math.floor(num);
alert(num);       // 12
Indicate the PHP function which returns the number of characters in string.
mb_strlen() count() stristr()
$str = "string with utf-8 chars åèö";
$nrchr = mb_strlen($str);
echo $nrchr;        // 30
Moving html element to a random direction

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