Javascript Course

The JavaScript function presented in this page can be used to Detect when ScrollBar reaches the bottom of the page.
This function is useful when you want to execute some JavaScript code when the user scrolls till the bottom of page, for example to display another content, making an infinite scroll.
Here is the function, named whenScrlBottom(). It must be accessed by the "onscroll" event.
// function to detect when scroollbar reaches the bottom of page
var whenScrlBottom = function() {
  // https://coursesweb.net/javascript/
  var win_h = (self.innerHeight) ? self.innerHeight : document.body.clientHeight;    // gets window height

  // gets current vertical scrollbar position
  var scrl_pos = window.pageYOffset ? window.pageYOffset : document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop;

  // if scrollbar reaces to bottom
  if (document.body.scrollHeight <= (scrl_pos + win_h)) {
    alert('Bottom');
  }
}

// register event on scrollbar
window.onscroll = whenScrlBottom;

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which tag defines the clickable areas inside the image map?
<map> <img> <area>
<img src="image.jpg" usemap="#map1">
<map name="map1">
  <area shape="rect" coords="9, 120, 56, 149" href="#">
  <area shape="rect" coords="100, 200, 156, 249" href="#">
</map>
Which CSS property defines what is done if the content in a box is too big for its defined space?
display overflow position
#id {
  overflow: auto;
}
Click on the event which is triggered when the mouse is positioned over an object.
onclick onmouseover onmouseout
document.getElementById("id").onmouseover = function(){
  document.write("Have Good Life");
}
Indicate the PHP variable that contains data added in URL address after the "?" character.
$_SESSION $_GET $_POST
if(isset($_GET["id"])) {
  echo $_GET["id"];
}
Detect when ScrollBar reaches the bottom of the page

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