function rgbToHex(R,G,B) {return toHex(R)+toHex(G)+toHex(B)}
function toHex(n) {
n = parseInt(n,10);
if (isNaN(n)) return "00";
n = Math.max(0,Math.min(n,255));
return "0123456789ABCDEF".charAt((n-n%16)/16)
+ "0123456789ABCDEF".charAt(n%16);
}
Notes: The script parses the input
R,
G,
B values as integers using the standard function
parseInt(string,10); the second, optional argument
10 specifies that the value must be parsed as a decimal number. (If we omit the
10, the script would still work, except for some input values starting with
0, e.g.
009 or
011, where it might incorrectly assume
octal input.)
We use the standard functions
Math.min and
Math.max to make sure that the input values are within the range from 0 to 255. The interested reader might notice that a nicer way to convert
n to a hexadecimal string is to use
n.toString(16); however, the above code was written back in the ancient era when JavaScript 1.0 was still around, and the construct
n.toString(16) won't work in JavaScript 1.0!
