Tag Archives: javascript

javascript programming

What is Transpilation?

Transpilation is the process of converting code written in one programming language to another. Transpilation to JavaScript is a common approach to enabling languages to run in the browser, but often provides limited functionality.

JavaScript – The canvas sin code.

Today’s tutorial is about using canvas with the javascript script with the use of the mathematical sin function. This JavaScript code is simple to understand. Start with the HTML5 source code:

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<canvas id="id_canvas"></canvas>

Use this javascript code:

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can=document.getElementById("id_canvas");
x=can.getContext("2d");
can.width=640;
can.height=480;
S=Math.sin;
frames = 30;
w2 = 640;
update_draw=()=>{
for(x.fillRect(0,0,i=(w=w2),i);i--;){
x.clearRect(S(time_run),S(time_run)*w,w,1)
}
time_run+=1/frames
requestAnimationFrame(update_draw)
}
time_run=0
update_draw()

The definition of variables and function sin is easy to understand. The first fillRect will create the area… Read More »

HTML5 – remove outline around input.

This tutorial is about how to remove outline style around input boxes in chrome using CSS. The answer is very simple, use this:

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input:focus, textarea:focus, select:focus{
        outline: none;
    }

See the Pen Input_remove_outline by Cătălin George Feștilă (@catafest) on CodePen.

JavaScript – How to use geolocation.

Using HTML Geolocation with the javascript programming language is very easy. The example uses the navigator.geolocation and gets all data for your geolocation. Into your HTML page add this javascript:

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<script>
 
function mapServiceProvider(lat, long) {
  document.writeln("Your geolocation position is:<br>")
  document.writeln("Latitude = "+lat+"; Longitude = "+long);
}
 
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(
function (position) {  
mapServiceProvider(position.coords.latitude,position.coords.longitude);
},
// next function is the error callback
function (error)
{
switch(error.code)
{
case error.TIMEOUT:
alert ('Timeout');
break;
case error.POSITION_UNAVAILABLE:
alert ('Position unavailable');
break;
case error.PERMISSION_DENIED:
alert ('Permission denied');
break;
case error.UNKNOWN_ERROR:
alert ('Unknown error');
break;
}
}
);
//}
} else {
  alert("Error: geolocation not supported in your browser!");
}
</script>

The result can be found at my codepen account.