Number to fraction

num2fraction.js

//最大公约数
function gcd(a, b) {
  if (b === 0) return a
  return gcd(b, a % b)
}

function num2fraction(num) {
  if (num === 0) return 0

  if (typeof num === "string") {
    num = parseFloat(num)
  }

  var number = num * 100000000
  //分子
  var numerator = number / gcd(number, 100000000)
  //分母
  var denominator = 100000000 / gcd(number, 100000000)

  //分数
  var fraction = numerator + '/' + denominator

  return fraction
}

num2fraction.prototype = {
  toString: function() {
    return (this.denominator === 1) ? this.numerator.toString() : (this.numerator + '/' + this.denominator)
  }
}

module.exports = num2fraction

console.log(num2fraction(0))            // => 0
console.log(num2fraction(1.3))          // => 13/10
console.log(num2fraction(1.4))          // => 7/5
console.log(num2fraction(1.5))          // => 3/2
console.log(num2fraction(2))            // => 2/1
console.log(num2fraction(3))            // => 3/1
console.log(num2fraction('1.5px'))      // => 3/2
console.log(num2fraction(3).toString()) // => 3/1