hex2rgb, a hex to rgb JavaScript string conversion function that's faster than binary operators and bit shifting...

hex2rgb.js

// 6 May 2024
// hex to rgb

// made you look

// originary defamatory statement
// https://twitter.com/the_moisrex/status/1787444601571221892

// uncomplicated, performs well enough (suite runs under 1ms).
// supports 3 or 6 character strings with or without leading octothorpe.
// returns "rgb(DD, DD, DD)" string.

function hex2rgb(v) {
  var s = ("" + v).replace(/[^\d^A-F]/gi, '') + "";

  var a = s.length == 3
    ? [
        parseInt(s[0] + s[0], 16),
        parseInt(s[1] + s[1], 16),
        parseInt(s[2] + s[2], 16)
      ]
    : [
        parseInt(s[0] + s[1], 16),
        parseInt(s[2] + s[3], 16),
        parseInt(s[4] + s[5], 16)
      ];

  return "rgb(" + a.join(",") + ")";
}


/* test it out */


~(function () {
  console.time("test");
  var start = performance.now();

  var tests = [
    {},
    { toString() { return "ABC"} },
    ['#ABC'],
    ["#", 'a', 'b', 'c'],
    "#7f11e0",
    "#fff",
    "#000",
    "#abc",
    "ABC",
    "1234",
    "#frederick",
    "dfkaye"
  ];

  var results = tests.map(hex2rgb);

  var end = performance.now() - start;
  console.timeEnd("test");
  console.log("perf:", end);

  console.log(JSON.stringify(results, null, 2));
  /*
  [
    "rgb(190,203,236)",
    "rgb(170,187,204)",
    "rgb(170,187,204)",
    "rgb(170,187,204)",
    "rgb(127,17,224)",
    "rgb(255,255,255)",
    "rgb(0,0,0)",
    "rgb(170,187,204)",
    "rgb(170,187,204)",
    "rgb(18,52,NaN)",
    "rgb(254,222,12)",
    "rgb(223,174,NaN)"
  ]
  */
})();