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Convert decimal to fractions

I am working on a “toy problem” where I have to write a JavaScript function that converts the decimal to a fraction and returns it as a string. For example: fractionConverter (2.75) should return "11/4".

Here is my code:

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);
}

Sorry for the formatting. Anyway, I get a weird rejection of the specification. The function returns the correct values ​​for the following numbers: 0.5, 3, 2.5, 2.75, -1.75 and 0.88. For some reason, however, it does not work on .253213. It returns 1266065/5000000 instead of 253213/1000000. Not quite sure why.

thanks

+4
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5 answers

Javascript .

node:

0.253213 * 1000000

:

253213.00000000003


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

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

.

, , , 0,3333333333 1/3.

, , , javascript 10 ^ 15 10 ^ 16.

(( * bigNumber) > 2 ^ 53), .

+2

@william, , script .

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);

HTML      

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

</html>
+2

, . . , .

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>
Hide result
+1

, ECMAscript Decicals. , , .

javascript :

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()

, , Python :

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()
+1

Erik Garrison fraction.js, .

1.75,

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
0

Source: https://habr.com/ru/post/1626475/

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