addTwoDigits.js

/*

CodeSignal Add Two Digits Problem:

You are given a two-digit integer n. Return the sum of its digits.

Example

For n = 29, the output should be
addTwoDigits(n) = 11.

Input/Output

[execution time limit] 4 seconds (js)

[input] integer n

A positive two-digit integer.

Guaranteed constraints:
10 ≤ n ≤ 99.

[output] integer

The sum of the first and second digits of the input number.
*/

// Solution :

function addTwoDigits(n) {
  // Takes number in n and converts it to string i.e. 29 becomes '29'
  let str = n.toString();
  // Creates array where each string in str is an array element i.e 29 becomes ['2', '9']
  let arr = str.split('');
  
  let arr0 = arr[0];
  let arr1 = arr[1];
  
  // Unary operator converts ['2', '9'] to [2, 9] when added
  // Adds 2 + 9 to get correct answer of 11
  return +arr[0] + +arr[1];
}