text: console.log('9999999999999999') // It's print 9999999999999999
  console.log(9999999999999999n) // It's print 9999999999999999, but BigInt is not supported in most browsers (https://caniuse.com/?search=BigInt)
  console.log(9999999999999999) // It's print 10000000000000000
  
  /**
   * Check string is valid number.
   * @constructor
   * @param {string} number - The number want to validate.
   * @returns {boolean} is valid number
   */
  function isNumber(number) {
      if (
        typeof number !== 'string' ||
        (
          !isNaN(number) &&
          number.indexOf('e') !== -1
        )
      ) {
          return false
      }
      return !isNaN(number)
  }
  
  console.log(isNumber('9999999999999999')) // true
  console.log(isNumber('1e+2')) // false
  console.log(isNumber(9999999999999999n)) // false
  console.log(isNumber(9999999999999999)) // false
  
  /**
   * Number, is Greater than.
   * @constructor
   * @param {string} a - The number want to compare.
   * @param {string} b - Number to compare from "a".
   * @returns {boolean} "a" is greater than "b"
   */
  function isGreater(a, b) {
      if ( isNumber(a) && isNumber(b) ) {
          if ( a.length > b.length ) return true
          if ( a.length === b.length ) {
              // Object for convert string to number
              const numbers = {
                '0': 0,
                '1': 1,
                '2': 2,
                '3': 3,
                '4': 4,
                '5': 5,
                '6': 6,
                '7': 7,
                '8': 8,
                '9': 9,
              }
              let numA = 0,
                  numB = 0
  
              // check the "greater than" of the first number then move on to the second number and so on (from the front)
              for (let i = 0; i < a.length; i++) {
                  // Convert string to number by accessing {numbers} object
                  numA = numbers[a.substr(i, 1)]
                  numB = numbers[b.substr(i, 1)]
                  if ( numA > numB ) return true
              }
          }
      }
      return false
  }
  
  console.log(isGreater('12', '1') === true) // true
  console.log(isGreater('1', '1') === false) // true
  console.log(isGreater('2', '2') === false) // true
  console.log(isGreater('1', '2') === false) // true
  console.log(isGreater('2', '1') === true) // true
  