Sum Strings As Integers

sum-strings-as-integers.js

function sumStrings(a,b) { 
  let result = '';
  const long = (a.length < b.length) ? b : a;
  let short = (long === a) ? b : a;
  let pass = 0;
  while (long.length > short.length) {
    short = '0' + short;
  }
  for (let i = long.length - 1; i >= 0; i--) {
    let sum = parseInt(long[i]) + parseInt(short[i]) + pass;
    pass = (sum >= 10 && i !== 0) ? (sum - sum % 10) / 10 : 0;
    //console.log(long[i] + '+' + short[i] + ': sum: ', sum, ' | pass: ', pass);
    sum -= pass * 10;
    result = sum.toString() + result;
  }
  while (result.indexOf('0') === 0) {
    result = result.substr(1, result.length - 1);
  }
  return result;
}

SumStringsAsIntegers.markdown

Sum Strings As Integers

Sums provided strings, consisting of integers, as integers.

A script by V.

License.