hexToRGB
Converts a color code to an rgb() or rgba() string if alpha value is provided.
- Use bitwise right-shift operator and mask bits with
&(and) operator to convert a hexadecimal color code (with or without prefixed with#) to a string with the RGB values. - If it's 3-digit color code, first convert to 6-digit version.
- If an alpha value is provided alongside 6-digit hex, give
rgba()string in return.
const hexToRGB = hex => {
let alpha = false,
h = hex.slice(hex.startsWith('#') ? 1 : 0);
if (h.length === 3) h = [...h].map(x => x + x).join('');
else if (h.length === 8) alpha = true;
h = parseInt(h, 16);
return (
'rgb' +
(alpha ? 'a' : '') +
'(' +
(h >>> (alpha ? 24 : 16)) +
', ' +
((h & (alpha ? 0x00ff0000 : 0x00ff00)) >>> (alpha ? 16 : 8)) +
', ' +
((h & (alpha ? 0x0000ff00 : 0x0000ff)) >>> (alpha ? 8 : 0)) +
(alpha ? `, ${h & 0x000000ff}` : '') +
')'
);
};