BIN2OCT Function

BIN2OCT.js

// Copyright (c) 2012 Sutoiku, Inc. (MIT License)

function BIN2OCT(number, places) {
  // Return error if number is not binary or contains more than 10 characters (10 digits)
  if (!/^[01]{1,10}$/.test(number)) return '#NUM!';

  // Ignore places and return a 10-character octal number if number is negative
  var stringified = number.toString();
  if (stringified.length === 10 && stringified.substring(0, 1) === '1') {
    return (1073741312 + parseInt(stringified.substring(1), 2)).toString(8);
  }

  // Convert binary number to octal
  var result = parseInt(number, 2).toString(8);

  // Return octal number using the minimum number of characters necessary if places is undefined
  if (typeof places === 'undefined') {
    return result;
  } else {
    // Return error if places is nonnumeric
    if (isNaN(places)) return '#VALUE!';
    
    // Return error if places is negative
    if (places < 0) return '#NUM!';
    
    // Truncate places in case it is not an integer
    places = Math.floor(places);

    // Pad return value with leading 0s (zeros) if necessary (using Underscore.string)
    return (places >= result.length) ? _s.repeat('0', places - result.length) + result : '#NUM!';
  }
}