BIN2DEC Function

BIN2DEC.js

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

function BIN2DEC(number) {
  // Return error if number is not binary or contains more than 10 characters (10 digits)
  if (!/^[01]{1,10}$/.test(number)) return '#NUM!';
  
  // Convert binary number to decimal
  var result = parseInt(number, 2);
  
  // Handle negative numbers
  var stringified = number.toString();
  if (stringified.length === 10 && stringified.substring(0, 1) === '1') {
    return parseInt(stringified.substring(1), 2) - 512;
  } else {
    return result;
  }
}