5kyu-rgbToHexConversion.js

'use strict';

// Source: https://www.codewars.com/kata/513e08acc600c94f01000001

// DESCRIPTION:

// The rgb function is incomplete. Complete it so that passing in RGB decimal 
// values will result in a hexadecimal representation being returned. Valid 
// decimal values for RGB are 0 - 255. Any values that fall out of that range 
// must be rounded to the closest valid value.

// Note: Your answer should always be 6 characters long, the shorthand with 3 
// will not work here.

// The following are examples of expected output values:

// rgb(255, 255, 255) // returns FFFFFF
// rgb(255, 255, 300) // returns FFFFFF
// rgb(0,0,0) // returns 000000
// rgb(148, 0, 211) // returns 9400D3


function rgb(r, g, b){
  const colors = [r, g, b];

  for (let i = 0; i < 3; ++i) {
    colors[i] = colors[i] < 0 ? 0 : colors[i] > 255 ? 255 : colors[i];
    colors[i] = colors[i].toString(16).toUpperCase();
    if (colors[i].length === 1) colors[i] = '0' + colors[i];
  }

  return colors.join('');
}