How to fix javascript array writing problem?

Question

When i try to write a function result to an array tmp, with specified index, the whole array changes to a number.

I tried running the function hex2dec alone, which works like intended and i tried writing a constant to it, which works too. But when i replaced the constant with the function result, the array became 15. (depends on function input)

function clrData(data) {
  data = data.split("");
  tmp = [0, 0, 0];
  tmp[0] = hex2dec(data[0] + data[1]);
  tmp[1] = hex2dec(data[2] + data[3]);
  tmp[2] = hex2dec(data[4] + data[5]);

  return tmp;
}

clrData("FFFFFF") should result in [255, 255, 255] but results in 15

function clrData(data) {
  data = data.split("");
  tmp = [0, 0, 0];
  tmp[0] = hex2dec(data[0] + data[1]);
  tmp[1] = hex2dec(data[2] + data[3]);
  tmp[2] = hex2dec(data[4] + data[5]);

  return tmp;
}

function plc(num) {
  plc = 0;
  
  while (num > 0) {
    num /= 10;
    plc++;
    num = Math.floor(num);
  }
  
  return plc;
}

function hex2dec(num) {
  num = num.toString();
  numArr = num.split("");
  
  num2 = 0;
  for (i=0; i<numArr.length; i++) {
    if (numArr[i] == "0" || numArr[i] == "1" || numArr[i] == "2" || numArr[i] == "3" || numArr[i] == "4" || numArr[i] == "5" || numArr[i] == "6" || numArr[i] == "7" || numArr[i] == "8" || numArr[i] == "9") {
      tmp = Number(numArr[i]);
    } else {
      switch (numArr[i]) {
        case "a":
        case "A":
          tmp = 10;
          break;
        case "b":
        case "B":
          tmp = 11;
          break;
        case "c":
        case "C":
          tmp = 12;
          break;
        case "d":
        case "D":
          tmp = 13;
          break;
        case "e":
        case "E":
          tmp = 14;
          break;
        case "f":
        case "F":
          tmp = 15;
          break;
        default:
          tmp = 0;
      }
    }

    num2 += Math.pow(16, (numArr.length-1) - i) * tmp;
  }

  return num2;
}

<input id="finput" value="FFFFFF"><button onClick="this.innerHTML=clrData(document.getElementById('finput').value)">Activate!</button>

If you gonna work with color you better use clamped array - developer.mozilla.org/ru/docs/Web/JavaScript/Reference/… — lucifer63
– lucifer63, Commented Jul 30, 2019 at 19:04

Nina Scholz · Accepted Answer · 2019-07-30 17:39:57Z

1

You could get groups of two characters and map the integer value.

function clrData(data) {
    return data.match(/../g).map(h => parseInt(h, 16));
}

console.log(clrData("FFFFFF"));

answered Jul 30, 2019 at 17:39

Nina Scholz

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