Question

我正在解决玩具问题＆＃34;我应该编写一个JavaScript函数，将小数转换为分数并将其作为字符串返回。例如：fractionConverter（2.75）应返回＆＃34; 11/4＆＃34;。

这是我的代码：

function fractionConverter (number) {
  if (number > 0) {
    var isNegative = false;
  } else if (number < 0) {
    var isNegative = true;
  }

  number = Math.abs(number);

  if (number % 1 === 0) {
    var finalFrac = number + "/1";
  } else {
    for (var i = 2; i < 10000000000; i++) {
      if ((i * number) % 1 === 0) {
        var finalFrac = (i * number) + "/" + i;
      }
      if (finalFrac) { break; }
    }
  }

  var getFrac = function(numString, bool) {
    if (!bool) {
      return numString;
    } else {
       return "-" + numString;
    }
  }

  return getFrac(finalFrac, isNegative);
}

抱歉格式化。无论如何，我得到一个奇怪的规格失败。该函数返回以下数字的正确值：0.5,3,2.5,2.75，-1.75和.88。然而，出于某种原因，它在0.253213上失败了。它返回1266065/5000000而不是253213/1000000。不太清楚为什么。

由于

Answer 1

我正在改善@ william的回答，我认为这个脚本可以让你减少分数。

function fractionConverter(number) {
  var fraction = number - Math.floor(number);
  var precision = Math.pow(10, /\d*$/.exec(new String(number))[0].length);
  var getGreatestCommonDivisor = function(fraction, precision) {
    if (!precision)
      return fraction;
    return getGreatestCommonDivisor(precision, fraction % precision);
  }
  var greatestCommonDivisor = getGreatestCommonDivisor(Math.round(fraction * precision), precision);
  var denominator = precision / getGreatestCommonDivisor(Math.round(fraction * precision), precision);
  var numerator = Math.round(fraction * precision) / greatestCommonDivisor;

  function reduce (numer,denom) {
    for (var i = 2; i >= 9; i++) {
      if ((numer%i===0) && (denom%i)===0) {
        numerator=numer/i;
        denominator=denom/i;
        reduce(numerator,denominator);
      };
    };
  }
reduce(numerator,denominator);
  return numerator + "/" + denominator;
}

document.getElementById("output").innerHTML = fractionConverter(0.24888);

这是HTML

<body>
  <p id="output"></p>
</body>

</html>

Answer 2

Javascript不能准确处理浮点数。

我尝试将其输入节点：

0.253213 * 1000000

我得到了这个：

253213.00000000003

以下是测试乘数的另一种方法

var bigNumber = Math.pow(10,8);

var isDivisible = (Math.round(i * number * bigNumber)/bigNumber % 1) == 0;

这对你有所帮助。

如果您希望0.333333333被视为1/3，这也可以按您预期的方式工作。

一个问题是你可以拥有的最高整数是javascript介于10 ^ 15和10 ^ 16之间。

如果（（number * bigNumber）> 2 ^ 53）这将无效。

Answer 3

我完全改变了代码的结构，但这个解决方案确实有效。它基于this线程的代码。我希望这会有所帮助。

function fractionConverter(number) {
  var fraction = number - Math.floor(number);
  var precision = Math.pow(10, /\d*$/.exec(new String(number))[0].length);
  var getGreatestCommonDivisor = function(fraction, precision) {
    if (!precision)
      return fraction;
    return getGreatestCommonDivisor(precision, fraction % precision);
  }
  var greatestCommonDivisor = getGreatestCommonDivisor(Math.round(fraction * precision), precision);
  var denominator = precision / greatestCommonDivisor;
  var numerator = Math.round(fraction * precision) / greatestCommonDivisor;

  return numerator + "/" + denominator;
}

document.getElementById("output").innerHTML = fractionConverter(0.253213);

<!DOCTYPE html>
<html>

<body>
  <p id="output"></p>
</body>

</html>

Answer 4

这个答案的警告是ECMAscript不能很好地处理小数。另请注意，以下内容主要是伪代码，但应使用小修复。

以下是此问题的JavaScript解决方案：

var decimal_to_fraction = {
  "numerator": 0,
  "denominator": 0,
  "simplified_numerator": this.numerator,
  "simplified_denominator": this.denominator,
  "init": function(numerator, denominator){
    this.numerator = numerator
    this.denominator = denominator
  },
  "get_divisor": function(numerator, denominator){
    var divisor = 0;
    var divisors = [1, 2, 3, 4, 5];

    for (i in divisors) {
      if (!(numerator % divisor) && !(denominator % divisor)) {
        divisor = i;
        break
      }
    }

    return divisor
  },
  "calculate_fraction": function() {
    var simplified = false;
    divisor = this.get_divisor(numerator_denominator);

    if (divisor) {
      while (simplified == false) {
        if (this.simplfieid_numerator / divisor and this.simplified_denominator / divisor) {
          this.simplified_numerator = simplified_numerator / divisor
          this.simplified_denominator = simplified_denominator / divisor
        } else {
          simplified = true
        }
      }
    }

    return (this.simplified_numerator, this.simplfieid_denominator)
  },
  "get_fraction": function() {
    this.calculate_fraction()

    fraction = "{0} / {1}".format(this.simplfieid_numerator, this.simplified_denominator"

    return fraction
  }

}

decimal_to_fraction.get_fraction()

如果您感到好奇，这是您解决问题的Python解决方案：

class DecimalToFraction(object):
    def __init__(decimal):
        self.numerator = decimal * 100
        self.denominator = 100
        self.simplified_numerator = self.numerator
        self.simplified_denominator = self.denominator

    def get_divisor(self, numerator, denominator):
        divisor = 0

        for i in range(0,5):
            if not numerator % divisor and not denominator % divisor:
                divisor = i
                break

        return divisor

    def calculate_fraction(self):
        simplified = False

        divisor = get_divisor(self.numerator, self.denominator)

        if divisor:
            while simplified == False:
                if self.simplified_numerator / divisor and self.simplfieid_denominator / divisor:
                    self.simplified_numerator = simplified_numerator / divisor
                    self.simplified_denominator = simplified_denominator / divisor
                else:
                    simplified = True

        return (self.simplified_numerator, self.simplified_denominator)


    def get_fraction(self):
        self.calculate_fraction()

        fraction = "{0} / {1}".format(self.simplified_numerator, self.simplified_denominator)

        return fraction


#d2f = DecimalToFraction(<decimal>)
#d2f.get_fraction()

Answer 5

您可以使用Erik Garrison的fraction.js库来执行此操作以及更多小数操作。

要做1.75，你可以做到

var f = new Fraction(1.75);
console.log(f.toFraction()); // Results "1 3/4" 
console.log(f.s * f.n + " / " + f.d); // Results "7 / 4"
console.log(f.toString()); // Results "1.75

将十进制转换为分数

5 个答案: