JavaScript: Extend a 3-digit color code to a 6-digit color code

JavaScript fundamental (ES6 Syntax): Exercise-20 with Solution

Write a JavaScript program to extend a 3-digit color code to a 6-digit color code.

• Use Array.prototype.map(), String.prototype.split() and Array.prototype.join() to join the mapped array for converting a 3-digit RGB notated hexadecimal color-code to the 6-digit form.
• Array.prototype.slice() is used to remove # from string start since it's added once.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const extend_Hex = shortHex =>
  '#' +
  shortHex
    .slice(shortHex.startsWith('#') ? 1 : 0)
    .split('')
    .map(x => x + x)
    .join('');

console.log(extend_Hex('#03f'));
console.log(extend_Hex('05a'));

Sample Output:

#0033ff
#0055aa

Pictorial Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-1-20 by w3resource (@w3resource) on CodePen.

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