Hexdecimal to decimal conversor

In this example below you will see how to do a Hexdecimal to decimal conversor with some HTML / CSS and Javascript

This awesome code was written by zLuck747, you can see more from this user in the personal repository.
You can find the original code on Codepen.io
• HTML
• JavaScript
``````<!DOCTYPE html>
<html lang="en" >

<meta charset="UTF-8">
<title>Hexdecimal to decimal conversor</title>

<body>

<html>
<body bgcolor = "black">
<center><FORM>
<INPUT TYPE="button" style="width:350px;height:60px; onClick="history.go(0)" VALUE="Calcular novo numero">
</FORM></center>
<center><font color = "white" size = "40"><i><h2> Hexdecimal to decimal conversor xD </h2></i></font></center>
<center><font color = "white" size = "35"><i><h3> Enjoy :D </h3></i></font></center>
</body>
</html>

<script  src="js/index.js"></script>

</body>

</html>
``````
``````
var c1 = '0';
var c2 = '0';
var c3 = '0';
var c4 = '0';

var input = prompt("input your hexdecimal number").toUpperCase();

switch(input.length) {
case 1:
var valueHexC1 = function() {
switch(input[0]) {
case '0':
c1 = 0;
break;
case '1':
c1 = 1;
break;
case '2':
c1 = 2;
break;
case '3':
c1 = 3;
break;
case '4':
c1 = 4;
break;
case '5':
c1 = 5;
break;
case '6':
c1 = 6;
break;
case '7':
c1 = 7;
break;
case '8':
c1 = 8;
break;
case '9':
c1 = 9;
break;
case 'A':
c1 = 10;
break;
case 'B':
c1 = 11;
break;
case 'C':
c1 = 12;
break;
case 'D':
c1 = 13;
break;
case 'E':
c1 = 14;
break;
case 'F':
c1 = 15;
break;
default:
console.log("Ha um problema com o primeiro caractere!");
}
}
valueHexC1();
var result = ( input + " === " + ( (c1 * 1) ) );
break;
//Finish Case length 1 (switch) global!
//Finish Case length 1 (switch) global!
case 2:
var valueHexC2 = function() {
switch(input[0]) {
case '0':
c1 = 0;
break;
case '1':
c1 = 1;
break;
case '2':
c1 = 2;
break;
case '3':
c1 = 3;
break;
case '4':
c1 = 4;
break;
case '5':
c1 = 5;
break;
case '6':
c1 = 6;
break;
case '7':
c1 = 7;
break;
case '8':
c1 = 8;
break;
case '9':
c1 = 9;
break;
case 'A':
c1 = 10;
break;
case 'B':
c1 = 11;
break;
case 'C':
c1 = 12;
break;
case 'D':
c1 = 13;
break;
case 'E':
c1 = 14;
break;
case 'F':
c1 = 15;
break;
default:
console.log("Ha um problema com o primeiro caractere!");
}
switch(input[1]) {
case '0':
c2 = 0;
break;
case '1':
c2 = 1;
break;
case '2':
c2 = 2;
break;
case '3':
c2 = 3;
break;
case '4':
c2 = 4;
break;
case '5':
c2 = 5;
break;
case '6':
c2 = 6;
break;
case '7':
c2 = 7;
break;
case '8':
c2 = 8;
break;
case '9':
c2 = 9;
break;
case 'A':
c2 = 10;
break;
case 'B':
c2 = 11;
break;
case 'C':
c2 = 12;
break;
case 'D':
c2 = 13;
break;
case 'E':
c2 = 14;
break;
case 'F':
c2 = 15;
break;
default:
console.log("Ha um problema com o segundo caractere!");
}
}
valueHexC2();
var result = ( input + " === " + ( (c1 * 16) + (c2 * 1) ) );
break;
//Finish Case length 2 (switch) global!
//Finish Case length 2 (switch) global!
case 3:
var valueHexC3 = function() {
switch(input[0]) {
case '0':
c1 = 0;
break;
case '1':
c1 = 1;
break;
case '2':
c1 = 2;
break;
case '3':
c1 = 3;
break;
case '4':
c1 = 4;
break;
case '5':
c1 = 5;
break;
case '6':
c1 = 6;
break;
case '7':
c1 = 7;
break;
case '8':
c1 = 8;
break;
case '9':
c1 = 9;
break;
case 'A':
c1 = 10;
break;
case 'B':
c1 = 11;
break;
case 'C':
c1 = 12;
break;
case 'D':
c1 = 13;
break;
case 'E':
c1 = 14;
break;
case 'F':
c1 = 15;
break;
default:
console.log("Ha um problema com o primeiro caractere!");
}
switch(input[1]) {
case '0':
c2 = 0;
break;
case '1':
c2 = 1;
break;
case '2':
c2 = 2;
break;
case '3':
c2 = 3;
break;
case '4':
c2 = 4;
break;
case '5':
c2 = 5;
break;
case '6':
c2 = 6;
break;
case '7':
c2 = 7;
break;
case '8':
c2 = 8;
break;
case '9':
c2 = 9;
break;
case 'A':
c2 = 10;
break;
case 'B':
c2 = 11;
break;
case 'C':
c2 = 12;
break;
case 'D':
c2 = 13;
break;
case 'E':
c2 = 14;
break;
case 'F':
c2 = 15;
break;
default:
console.log("Ha um problema com o segundo caractere!");
}
switch(input[2]) {
case '0':
c3 = 0;
break;
case '1':
c3 = 1;
break;
case '2':
c3 = 2;
break;
case '3':
c3 = 3;
break;
case '4':
c3 = 4;
break;
case '5':
c3 = 5;
break;
case '6':
c3 = 6;
break;
case '7':
c3 = 7;
break;
case '8':
c3 = 8;
break;
case '9':
c3 = 9;
break;
case 'A':
c3 = 10;
break;
case 'B':
c3 = 11;
break;
case 'C':
c3 = 12;
break;
case 'D':
c3 = 13;
break;
case 'E':
c3 = 14;
break;
case 'F':
c3 = 15;
break;
default:
console.log("Ha um problema com o terceiro caractere!");
}
}
valueHexC3();
var result = ( input + " === " + ( (c1 * 256) + (c2 * 16) + (c3 * 1) ) );
break;
//Finish Case length 3 (switch) global!
//Finish Case length 3 (switch) global!
case 4:
var valueHexC4 = function() {
switch(input[0]) {
case '0':
c1 = 0;
break;
case '1':
c1 = 1;
break;
case '2':
c1 = 2;
break;
case '3':
c1 = 3;
break;
case '4':
c1 = 4;
break;
case '5':
c1 = 5;
break;
case '6':
c1 = 6;
break;
case '7':
c1 = 7;
break;
case '8':
c1 = 8;
break;
case '9':
c1 = 9;
break;
case 'A':
c1 = 10;
break;
case 'B':
c1 = 11;
break;
case 'C':
c1 = 12;
break;
case 'D':
c1 = 13;
break;
case 'E':
c1 = 14;
break;
case 'F':
c1 = 15;
break;
default:
console.log("Ha um problema com o primeiro caractere!");
}
switch(input[1]) {
case '0':
c2 = 0;
break;
case '1':
c2 = 1;
break;
case '2':
c2 = 2;
break;
case '3':
c2 = 3;
break;
case '4':
c2 = 4;
break;
case '5':
c2 = 5;
break;
case '6':
c2 = 6;
break;
case '7':
c2 = 7;
break;
case '8':
c2 = 8;
break;
case '9':
c2 = 9;
break;
case 'A':
c2 = 10;
break;
case 'B':
c2 = 11;
break;
case 'C':
c2 = 12;
break;
case 'D':
c2 = 13;
break;
case 'E':
c2 = 14;
break;
case 'F':
c2 = 15;
break;
default:
console.log("Ha um problema com o segundo caractere!");
}
switch(input[2]) {
case '0':
c3 = 0;
break;
case '1':
c3 = 1;
break;
case '2':
c3 = 2;
break;
case '3':
c3 = 3;
break;
case '4':
c3 = 4;
break;
case '5':
c3 = 5;
break;
case '6':
c3 = 6;
break;
case '7':
c3 = 7;
break;
case '8':
c3 = 8;
break;
case '9':
c3 = 9;
break;
case 'A':
c3 = 10;
break;
case 'B':
c3 = 11;
break;
case 'C':
c3 = 12;
break;
case 'D':
c3 = 13;
break;
case 'E':
c3 = 14;
break;
case 'F':
c3 = 15;
break;
default:
console.log("Ha um problema com o terceiro caractere!");
}
switch(input[3]) {
case '0':
c4 = 0;
break;
case '1':
c4 = 1;
break;
case '2':
c4 = 2;
break;
case '3':
c4 = 3;
break;
case '4':
c4 = 4;
break;
case '5':
c4 = 5;
break;
case '6':
c4 = 6;
break;
case '7':
c4 = 7;
break;
case '8':
c4 = 8;
break;
case '9':
c4 = 9;
break;
case 'A':
c4 = 10;
break;
case 'B':
c4 = 11;
break;
case 'C':
c4 = 12;
break;
case 'D':
c4 = 13;
break;
case 'E':
c4 = 14;
break;
case 'F':
c4 = 15;
break;
default:
console.log("Ha um problema com o quarto caractere!");
}
}
valueHexC4();
var result = ( input + " === " + ( (c1 * 4096) + (c2 * 256) + (c3 * 16) + (c4 * 1) ) );