Convert a decimal number to a fraction / rational number

Question

In JavaScript, is there any way to convert a decimal number (such as 0.0002) to a fraction represented as a string (such as \"2/10000\")?

I

Answer 1

Very old question but maybe someone can find this useful. It's iterative, not recursive and doesn't require factorization

function getClosestFraction(value, tol) {
    var original_value = value;
    var iteration = 0;
    var denominator=1, last_d = 0, numerator;
    while (iteration < 20) {
        value = 1 / (value - Math.floor(value))
        var _d = denominator;
        denominator = Math.floor(denominator * value + last_d);
        last_d = _d;
        numerator = Math.ceil(original_value * denominator)

        if (Math.abs(numerator/denominator - original_value) < tol)
            break;
        iteration++;
    }
    return {numerator: numerator, denominator: denominator};
};